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OLD
CLASS
AGRIC
G
PASC
PRESENTED
THE UNIVERSITY OF TORONTO
/ f
Private Circulation.
HISTORY, AND PRESENT POSITION,
OF THR
ROTHAMSTED INVESTIGATIONS.
BY
PROFESSOR J. H. GILBERT, Ph.D., LL.D., F.RS.
SEEN BY
PRESERVATION
SERVICES
DATE
LONDON :
HARBISON & SONS, ST. MARTIN'S LANE,
PEINTBE8 IN OEDINART TO HEB MAJESTY.
1891.
CONTENTS.
PA as
Explanation ,. .. .. .. ,. .. .. 5
Introductory Remarks . . . . 6
I. The Continuous Growth of Wheat, in Broadbalk Field :
1. The Field Eesults 8
2. The Composition of the Crops . . . . . . 9
3. The Soils of the Wheat Plots 12
II. The Continuous Growth of Barley, in Hoosfield :
1. The Field Results 16
2. The Composition of the Crops . . . . . . 17
3. The Soils of the Barley Plots 19
III. The Continuous Growth of Leguminous Crops :
1. In Hoosfleld (the Crops, their Composition, and the
Soils) 21
2. In Geescroft Field (the Crops, their Composition,
and the Soils) 25
3. In Rich Garden Soil (the Crops, their Composition,
and the Soils) 28
IV. Experiments on the Continuous Growth of Root-Crops, in
Barnfield Common Turnips, Swedish Turnips, Sugar-
beet, and Mangel Wurel :
1. The Field Results, and the Composition of the
Crops 29
2. The Soils of the Root-crop Plots 31
V. The Continuous Growth of Potatoes, in Hoosfield :
1. The Field Results 32
2. The Composition of the Crops 32
VI. Wheat alternated with Fallow, in Hoosfield :
1. The Field Results 34
2. The Soils of the Wheat-Fallow Plot .. .. 34
VII. Experiments on Rotation, in Agdell Field :
1. The Field Results 35
2. The Composition of the Rotation Crops . . . . 36
3. The Soils of the Rotation Plots 36
VIII. The Experiments on the Mixed Herbage of Permanent
Grass-land. The Park :
1. The Field Results 38
2. The Composition, Botanical and Chemical, of the
Crops . . 39
3. The Soils of the Mixed Herbage Plots . . . . 40
A 2
IX. Experiments on Oats, in Geescroft Field. . . . . . 43
X. Experiments on the Alternation of Wheat and Beans, in
Geescroft Field 44
XI. Experiments on Barley and Clover, in Little Hoosfield. . 46
XII. Experiments on the Amount, and on the Composition,
of Rain, and of Land-drainage Waters . . . . 48
XIII. Experiments on the Question of the Fixation of Free
Nitrogen . . . . ..... . . . . . . 51
XIV. .Experiments on the _Feeding of Animals . . . . . . 53
XV. Supplementary Investigations in Connection with the
Subject of the Feeding of Animals :
1. Experiments on the Utilisation of Town Sewage . . 56
2. Experiments on the Malting Process, and on the
Comparative Feeding Value of Barley and Malt. . 57
3. Experiments on Ensilage . . . . . . . . 57
XVI. Summary, Papers to be written, &c. . . . . . . 60
APPENDIX.
Titles of Kothamsted Papers, with references, and dates of
publication .. .. .. .. .. .. .. 64
Rothamsted, June, 1891.
EXPLANATION.
IT has now for some time been known that Sir John
Bennet Lawes has set apart a sum of 100,000, the
Laboratory, and certain areas of land, for the continuance
of the Eothamsted Investigations after his death. In
furtherance of this object, Trustees were appointed, and
the necessary Trust Deed was executed, in February
1889 ; and, in accordance with the provisions of the
Deed, a Committee of Management has been appointed,
and has entered upon its duties. The Trustees are,
Sir John Lubbock, Bart., F.B.S., Lord Walsingham,
FB.S., and Dr. John Evans, Treasurer of the lioyal
Society. The Committee consists of nine members :
Dr. John Evans, Treas. E.S. (Chairman), Dr. Hugo
MuUer, F.E.S. (Treasurer), Professor M. Foster, Sec. E.S.,
and W. T. Thiselton Dyer, Esq., F.E.S., nominated by
the Eoyal Society; Professor H. E. Armstrong, F.E.S.,
nominated by the Chemical Society; William Car-
ruthers, Esq., F.E.S., late Pres. Linn. Soc., nominated
by the Linnean Society; Sir John H. Thorold, Bart., and
Charles Whitehead, Esq., F.L.S., nominated by the Eoyal
Agricultural Society of England ; also Sir J. B. Lawes
himself.
In view of this new arrangement for the future con-
duct of the Investigations, it was considered desirable
that I should draw up a somewhat detailed account of
their history, and their present position ; such as might
not only aid the members of the present Committee in
acquiring a clear view of their objects and scope, but
also serve as a permanent record for future reference.
The Eeport was printed by order of the Committee,
and after they had obtained as many copies as they
required, they kindly placed the type at the disposal of
Sir J. B. Lawes and myself, with permission to make
such alterations as might seem desirable, for wider
circulation, especially among those connected with
Agricultural Investigation, or Agricultural Education,
both in this country and abroad, to whom it is sup-
posed the document may be of interest and utility.
Accordingly, some changes in form and arrangement
have been made, and the record has been brought up
to date, for the purposes of the present issue. With
the exception of such changes, the report is essentially
the same as that presented, in 1889, to "The Lawes
Agricultural Trust Committee."
It should be further stated, that an Appendix has been
added (pp. 64-74), giving lists of Eothamsted papers
already published, arranged in two Series, and within
each Series numbered in chronological order. They also
show, both where each paper originally appeared, and
the date of its publication. These lists are similar to
those given in the " Memoranda " (see below), and they
are given here, not only for purposes of general refer-
ence, but especially to facilitate reference to the titles
of the papers, or to the papers themselves, which are
referred to in the Keport under the same numbers as
those in the lists.
INTRODUCTORY EEMAEKS.
I would in the first place say, that the annually
published " Memoranda of the Origin, Plan, and Results
of the Field and other experiments conducted on the Farm
and in the Laboratory" at Rothamsted, gives a great
deal of information as to what are the various lines
of experiment carried on, and the lists of published
papers there given (and in the Appendix hereto), show
what subjects have been more or less fully reported
upon.
In this annual Memorandum, there is first given a
general description of the lines of enquiry in progress,
then follow lists of the papers published, with full
reference to where they appeared, and then are given
summaries, chieHy in the Tabular form, and for the
most part brought up to date, relating to Eain and
Drainage, and to the results of the Field experiments,
on Wheat, Barley, Oats, various Root-crops, Potatoes,
Rotation, and Permanent Grass; also to Leguminous
crops, but so far as they are concerned numerical results
are not given. Careful attention should, however, be
given to the descriptions, lists, and summaries, in the
" Memoranda"
It is to be presumed that the areas of land trans-
ferred to the Trustees, indicate pretty clearly the
importance to be attached to the various Field experi-
ments which have been carried on, or are still in
progress. They are, accordingly, the experiments on
1. The continuous growth of Wheat, in Broadbalk
Field.
2. The continuous growth of Barley ; also those on
Leguminous crops, Wheat alternated with Fallow,
and Potatoes, in Hoos-field.
3. The continuous growth of Root-crops, in Barnfield.
4. Rotation of crops, in Agddl Field.
5. Permanent Grass, in The Park.
It will be observed that the scheme comprises experi-
ments with individual typical elements of a rotation of
crops, namely wheat and barley representing cereals,
various root-crops, and various leguminous crops ; also
experiments on the crops grown in an actual course of
Rotation. Experiments on the mixed herbage of per-
manent grass-land are also included. Thus, so far as
crops are concerned, the characteristic elements of our
agriculture are investigated, both as to their intrinsic or
individual characters, as shown by their growth year
after year on the same land under different conditions
as to manuring, and as to their relative or com-
plementary characteristics, as grown in rotation.
After careful consideration of the subject with Sir
J. B. Lawes, it was agreed, that the various experiments
enumerated, with perhaps the exception of those with
potatoes, must be considered as of substantially equal
importance ; that is if, as hitherto, questions of funda-
mental, permanent, and general, as distinguished from
those which are of passing, or local, interest, are to be
kept in view. It was further considered that, under
the same assumption, the laboratory investigations con-
nected with the field results, are not susceptible of any
great or material change, or reduction ; as the plan and
objects supposed, involve the keeping up of the
chemical history, both of the experimental crops, and
of the soils on which they are grown ; and that all that
can be done is, to consider what modifications or
reductions in the detailed conduct of the different
experiments are admissible, or may be desirable, within
the comparatively near future, without sacrificing the
main objects of enquiry.
In a letter received from Sir J. B. Lawes since the
above was written, he says " * * * looking forward
to the great questions which are being raised in regard
to exhaustion of soil, and restoration of fertility, I
certainly think that our soil samples, and their history,
take the first place in importance."
I will now briefly indicate the scope of the investiga-
tions, and what has been published, in connection with
each of the above enumerated subjects of experiment.
I. THE CONTINUOUS GROWTH OF WHEAT, IN
BROADBALK FIELD.
1. The Field Results.
The first experimental crop was harvested in 1844, so
that the crop of the present year, 1891, will be the
48th. But as the arrangement of the manuring of the
different plots was not thoroughly systematised until
1851-52, this is only the 40th year under substantially
the same plan as to manuring as now followed.
In the "Memoranda " is annually given a statement of
the manuring, and of the produce, of each plot, in the
immediately preceding season ; also the average pro-.
(luru of each plot over the first half, the second half,
and the total period up to date, commencing with the
ninth crop, that of 1852. The results so recorded are,
however, given numerically only, that is without com-
ment or discussion.
A selection of the results is annually given, and
discussed, in a letter published in the chief Daily,
Agricultural, and some other Journals, as the basis of
an estimate of the average Wheat crop of the United
Kingdom.
The field results have been discussed more or less
fully, and sometimes in reference to special points of
interest, in the papers, the titles of which are given in
the list, Series 1 in the "Appendix" and there numbered
1, 5, 7, 8, 9, 10, 18, 23, 24, 26, 27, 28, 29,31,38, 40, 43,
48, 49, 54, 60, 64, 65, 66, 68, 72, and 73.
The results have been the more fully given, and the
more systematically discussed, in Nos. 23 and 66 ; the
first of these giving, and discussing, the results of each
of the first twenty, and the second those of each of the
second twenty years, of the continuous growth.
It is to be supposed that occasions may arise for
partial discussions in reference to special points of
interest ; but that further systematic discussion will be
postponed until the conclusion of the third period of
twenty years of the experiments (1903), or possibly
only until the conclusion of the first 50 years of their
duration (1893).
2. The Composition of the Continuous Wheat Crops.
The plots now under experiment are numbered 2
to 20 inclusive ; but 3 of these are each divided into
2 separate experiments, raising the number to 22, and
12 of the remainder are each divided into 2, which are
now only duplicates, but which have a slightly different
manurial history in earlier years, and hence separate
samples have hitherto been taken for dry matter, ash,
10
and nitrogen determinations. There is also one un-
numbered plot (" intermediate ").
There are thus 19 + 3 -I- 12 + 1 = 35 samples of
grain, and the same number of straw, annually taken.
A given weight of each is partially dried, and stored,
the grain in bottles, and the straw (cut into chaff) in
parcels, for determinations of nitrogen, &c., when
required. Duplicate portions of each sample (both
grain and straw), are dried in a water bath, and after-
wards burnt to ash.
It is desirable to sample the produce as at present, at
least up to the end of the 40th year from 1852, namely
to 1891 inclusive. But, as 12 of the plots now divided
into " a" and " b" portions, although they have, respec-
tively, a slightly different past manurial history, have
for some time been substantially duplicates, it is
considered that the two divisions might, after the crop
of 1891, be thrown into one, both so far as separation
at harvest, and separate sampling, are concerned. These
12 plots are <-5ab, Qab, 7ab, Sab, llab, I2ab, 13ab, I4ab,
loab, IQab, 17 ab, and I8ab. This would reduce, both
the number of plots separately harvested, and the
number of samples of corn, and of straw, taken, from
35 each as at present, to 23 each.
The nitrogen is not determined at once, but when
needed for purposes of study or publication. Thus, in
the case of a selection of plots, the nitrogen has been
determined, in the grain and in the straw, of each of
the first 20 years of the 48 of the experiments ; also in
the case of a number of selected plots, in 4 of the
same 20 years representing respectively, two good
and two bad seasons. It has been determined in
the case of 7 selected plots in proportionally mixed
samples of the grain, and of the straw respectively, of
the 20 years 1852-71 ; in the case of 13 selected
plots, in proportionally mixed samples of the graii.,
and in that of 10 selected plots in proportionally mixed
samples of the straw, of the 10 years 1852-61 ; also in
the case of the grain of 13 selected plots, and of the
straw of 10, for the 10 years 1862-71 ; and in the case
11
of 11 selected plots, in the grain for the 10 years
1872-81. Further selections and determinations should
be made after the completion of another period of 10
years, that is to 1891 inclusive.
Many determinations of nitrogen, both in the wheat
grain, and its Mill products, and also in the straw, are
jjiven in No. 10 ; also in some other papers, and
especially in No. 65.
The duplicate ashes are in each case mixed, if the
results as to actual and percentage amount are suffi-
ciently accordant ; and if not a check quantity of the
dry produce is burnt.
From the collection of ashes so obtained, of the grain
and of the straw of each plot, in each year, 253 indi-
vidual, or " mixed year" samples have been submitted
to complete analysis. Thus, in the case of 3 selected
plots, the ashes (of both grain and straw), of each of the
last 16 of the first 20 years of the experiments have so
been analysed. In the case of 9 selected plots, the
ashes of the produce of 4 selected seasons, within the
same 20 years, have been analysed ; and in the case of
10 selected plots, proportionally made, " mixed-year "
samples of ash (of grain and of straw respectively),
have been analysed for the 10 years 1852-61, and
again for the 10 years 1862-71.
In the case of some plots, analyses of the ash of the
grain, and of the straw, respectively, representing the
10 years 1872-81, and the 10 years 1882-91 should be
made, in continuation of the results already obtained for
the two periods of 10 years each, up to 1871 inclusive.
The results of the 253 complete ash analyses already
made were published and discussed in 1884, in the
paper numbered 65 in the list. The results of many
of the nitrogen determinations were at the same time
given. A selection of ash analyses, and also many
determinations of nitrogen as above referred to, were
published in 1857, in the paper No. 10 in the list.
The special object of the selection of plots for the
determinations of the nitrogen, and of the composition of
the ash, of the produce, has been to ascertain and illustrate
12
the influence of exhaustion, manures, and variations of
season, on the development, and on the organic and
mineral composition, of the grain and of the straw,
respectively; and the results have proved to be of
much interest. It will be observed that nitrogen
*3
determinations have been made in selected cases up to
1881 inclusive, but ash analyses only up to 1871.
But, as has been stated, samples of the partially dried
produce (grain and straw) of each plot, each year, are
preserved for future selection for nitrogen determina-
tions or other examination of organic composition, and
the ashes are prepared and preserved for future selection
for ash analysis, as the progress of exhaustion, or the
influence of full supply, may indicate to be desirable.
3. The Soils of the Continuous Wheat Plots.
Unfortunately, the conditions of soil-sampling essen-
tial to render the analytical results available for the
discussion of many important questions, such as that of
the soil as a source of the nitrogen of vegetation, and
collateral points, which the continuous growth of crops
as at Eothamsted suggest, are only learnt by experience,
and are perhaps not yet realised anywhere else. Thus,
although the Broadbalk field soil was sampled as early
as 1846, only a few samples of the surface soil of
indefinite area, and of only approximately estimated
depth, were taken ; so that no acreage calculations can be
founded on the results, and no exact comparison made,
of the condition of the land at that time, and in subse-
quent years, when more careful samples were taken.
Samples of a definite area and depth were first taken
in 1856, but then only of the surface soil, and only
from 4 plots ; but from 8 places on each plot, a mixture
being made of the 8 samples in each case, and in this
mixture the nitrogen (by soda-lime), and the carbon,
have been determined.
In 1865 samples were taken from 11 plots, from
8 places on each; and in each case representing the.
13
first, the second, and the third 9 inches of depth. In
the mixture of the 8 samples from each plot, and to
each depth, the nitrogen has been determined, and in
some the carbon also. In a few also the nitrogen as
nitric acid was determined.
In July 1868, during drought, and in January 1869,
when the land was saturated, samples were taken from
3 plots, in each case to 12 depths of 3 inches each, or
to a depth of 36 inches in all ; and although the chief
object was to determine the difference in the amount of
water retained on the differently manured plots, at the
different depths, the nitrogen, and in some cases the
carbon, were also determined.
Lastly, in 1881, samples were taken from 20 plots,
in each case from 6 places on the plot, and in each to
3 depths of 9 inches, or to a total depth of 27 inches.
In the mixed samples representing, respectively, the soil
at each depth, from each differently manured plot, the
total nitrogen, the carbon, the nitrogen as nitric acid,
and in some cases the chlorine, have been determined.
Partial determinations have also been made in a few of
the individual or unmixed samples.
The nitrogen results relating to the surface soils, 9
inches deep, of the 11 plots sampled in 1865, were
published in No. 57, p. 137 (1881-82). The nitrogen in
10 of these, and in the same 10 in 1881, was giveii
in No. 60, p. 32 et seq. (1882).
The nitrogen as nitric acid in the soils was first
determined in 1866, in a few of the 1865 samples, and
the results were given in the original paper of which
No. 25 is the abstract ; and referred to in No. 60, p. 48.
The nitrogen as nitric acid in the soils of 4 of the
20 plots in which it was determined in the 1881 samples,
and at each of the 3 depths of 9 inches each, was given
in No. 6.0, p. 49 ; and for the whole 20 plots, to the 3
depths, in No. 64, p. 21 and context.
Determinations of nitrogen by soda lime have been
made in all the above-enumerated mixed samples of the
wheat field subsoils, and the results are of much
14
interest, as indicating the large amounts of nitrogen they
contain ; but owing to the great variation in the natural
character of the subsoil of one and the same plot at
different places, and even at closely contiguous spots,
the results are quite inapplicable for comparative
acreage calculations, either between plot and plot, or
the same plot at different periods, and they have there-
fore not been published in detail. This great natural
irregularity was very marked in the samples above
referred to, but it was still more so in the case of some
samples taken in 1887 from 3 plots in the same field to
the depth of 12 times 9 inches, = 108 inches, or 9 feet,
in all; and it has also been very marked in samples
taken to a great depth in other fields, as will be referred
to further on.
But, notwithstanding this difficulty, the results re-
lating to what may be called the migratory constituents
of subsoils, the nitric acid for example, are of great
interest and significance. On this ground alone, it is
extremely desirable that each of the wheat field plots
should be sampled before long say after the removal
of the fiftieth successive crop, to a considerable depth ;
certainly not less than to 8 times 9 inches, and perhaps
to 12 times 9, as has been done in some of the other fields.
If, however, the change in the harvesting and sampling
which has been above suggested, be adopted after the
removal of the crop of 1891, it would be desirable
that the soil-sampling should be undertaken after the
harvest of that year.
But, independently of determinations of nitric acid,
chlorine, &c., and notwithstanding the impossibility,
arising from natural irregularity in the character of the
subsoils, of judging from determinations of the total
nitrogen in them, of the degree in which the subsoils
of the different plots, or of the same plot at different
periods, have yielded up (or acquired), nitrogen, it is of
great importance that samples should in future/ as in
the past, be carefully taken, and preserved ; in the hope
that, in the course of time, lines of investigation may
be determined upon, which will show the difference, if
15
any, in the condition of the remaining nitrogen of the
subsoils, according to the comparative history of the
plots ; and so enable a judgment to be formed, of the
degree in which the organic nitrogen has already been
attacked and has yielded up nitrogen in an available
form. It may be that any such method as here sup-
posed, may involve the action of nitrifying, or of other
organisms, of solvents, such as acids, and especially
organic acids, perhaps determining the character and
composition of the matters dissolved, or some quite
different method may be indicated, or the difference in
the relation of the carbon to the nitrogen, may be found
to have significance. But whatever line investigation
of the point may indicate, the desideratum is, in defect
of trustworthy evidence on the point derived from the
determination of the total nitrogen of the subsoils, to
determine by some other means, as between plot and
plot of known history, or as between the same plot at
different periods of its history, whether, and as far as
possible in what degree comparatively, the subsoil
nitrogen has been subject to loss, or it may be in some
cases to gain. It is obviously of interest, too, to
endeavour to get a clue to the changes that take place
in the mineral composition of the subsoils also.
These points may prove to be of importance so far as
the subsoils of the plots which have grown wheat, or
other cereals, for many years in succession, are con-
cerned, and especially in the case of those where such
crops have been so grown without any nitrogenous
manure. But such lines of enquiry, if at all successful,
promise much more fruitful results in the case of soils
where other crops, and especially where crops of the
Leguminous family have grown ; whilst those relating
to Gramineous crop soils will probably be chiefly of
interest in contrast or comparison with those relating to
the soils where crops of other families have grown.
At any rate it is essential to bear in mind, that there
is nowhere else, such soil and crop history, as at
Eothamsted ; and that the collection and preservation
of samples of the experimental soils, subsoils, and crops,
16
should not be limited by the exigencies or possibilities
of existing lines of investigation or discussion.
I have referred to these points here, as they naturally
arise in connection with the question of the wheat field
soils and subsoils ; but, as has been intimated above,
they will probably prove of greater interest and im-
portance in connection with the soils of other crops,
and having indicated the points here, I may refer to
them more briefly when considering the history of other
fields and crops. I have also gone into more detail in
regard to other points in connection with the wheat
experiments, which, mutatis mutandis, will apply to the
other fields and crops, and which therefore may be
treated more briefly so far as they are concerned.
In conclusion in regard to the wheat experiments, as
has been indicated, most of the results relating to the
total nitrogen of the surface soils, and most of those
relating to the nitrogen as nitric acid, in both surface
and subsoils, have already been published ; but from
what has been said it will be readily understood why
the results relating to the total nitrogen of the subsoils
have not been recorded, but have only been used as a
means of forming approximate estimates of the total
amount of combined nitrogen existing to given depths,
on a given area.
It should be added that a rdsumt, both of the Field
and the Laboratory results relating to wheat, is given in
No. 68, published in 1884
II. THE CONTINUOUS GROWTH OF BARLEY, IN
HOOSFIELD.
1. The Field Eesults.
The fortieth crop of barley in succession on the same
land, without manure, with farmyard manure, and with
different chemical manures, is now growing (April
1891). A summary of the results is annually given
in the " Memoranda" It will there be seen that
17
there are 5 main series, of 4 plots each, and there are
besides, 9 other plots, making in all 29. The descrip-
tion of the manuring of each plot, given to the left of
the columns of figures, taken together with the foot-
notes, shows the manurial history of the plots from the
commencement of the experiments in 1852. As in the
case of the wheat, the produce on each plot in the
immediately preceding season, also the average produce
over the first half, the second half, and the total period
up to date, is thus annually given.
In 1857, the results of the first 6 years of the con-
tinuous growth of barley, were discussed in the paper
numbered 11 in the list (Series 1), and in the same
paper the composition of the crops was also considered,
so far as the percentages of dry substance, mineral
matter, and nitrogen, are concerned.
In No. 33, published in 1873, the results obtained in
each of the first twenty years are recorded and discussed,
both so far as the influence of season, and that of the
different manures, are concerned.
The results obtained with barley were also discussed
in regard to special points of interest, in No. 35, pub-
lished in 1875. Lastly, in 1886, a re'sume' of the results
obtained in the 34 years to 1885 inclusive, was given in
No. 71, in which tne influences of exhaustion, manures,
and variations of season, both on the amounts of produce,
and on the composition of the crop, are illustrated.
The second period of twenty years of the barley
experiments will be completed with the harvest of the
present year, 1891 ; and the results for that period might
suitably be reported upon as soon as the requirements
of other subjects on hand will permit. Or some special
question may arise requiring partial publication. In the
meantime the field results should be annually given in
the tabular form in the "Memoranda" as heretofore.
2. The Composition of the Continuous Barley Crops.
Samples of the grain and of the straw of the barley
from each of the 29 plots in Hoosfield are annually
B
taken. A given weight of each is partially dried for
preservation, for nitrogen determinations, or for other
organic examination ; and duplicate portions are dried
at 100, the dry matter determined and recorded, and
then the duplicate portions are burnt to ash, the amounts
of ash recorded, and the ashes preserved.
There are practically no duplicate plots; so that,
so long as the experiments are continued, there
should be very little reduction, either in the separate
harvesting, or the separate sampling. After the 40th
crop, however, it may be considered whether crop-
samples need still be taken from the produce of plots
IN, 2N, 50, 5A, M, and 6-2, or whether in the case
of some of these the sampling might not be dis-
continued. Samples should certainly still be taken
from the grain, and from the straw, of Plots 6-1, 7-1,
7-2, and the other 20 plots. The utmost reduction in
sampling that can be suggested is, therefore, from 29 of
grain and 29 of straw, as at present, to 23 of each after
the 40th crop.
Fewer determinations of nitrogen have been made in
the grain and straw of barley than in those of wheat,
and most of those which have been made are in "mixed-
plot " or " mixed-year " samples ; that is on mixtures
made proportionally to the amount of produce in each
case, from several plots in one year, or from one plot
over several years. The results on the "mixed-plot"
samples were published in No. 11 as before referred
to, but those on the " mixed-year " samples have not yet
been published, and will probably be reserved until
the results of the complete ash-analyses are given in
detail.
Complete ash-analyses have been made in the case of
14 grain and 44 straw ashes, selected for the illustration
of the influence of exhaustion, manuring, and variations
of season, on the mineral composition of the crop ; those
illustrating the influence of season, being from the
produce of individual or mixed plots, in individual
years, and those illustrating that of exhaustion and
manuring being from "mixed-year 1 ' samples, covering
19
consecutive periods of 10, 10, and 5 years, 1852 to 1876
inclusive. Selections from the results of most of these
ash-analyses have been published in No. 71 (1886), and
they have proved to be of much interest.
It is very desirable that complete ash-analyses, and
nitrogen determinations, should soon be made in the
case of " mixed-year " samples, of the grain and of the
straw separately, especially of Plots 2A, and 4A, but
also of Plots 1A and 1AA, for the five years 1877-81,
for the five 1882-86, and for the five 1887-91 (or
for the 10 years 1882-91); in continuation of the
results previously obtained for 10, 10, and 5 years
(1852-76), as above referred to, for the further illus-
tration of the influence of. exhaustion, and of full
supply, on the amount, and on the composition, of the
produce.
There can be no doubt that it is desirable to continue
to take and to preserve samples of the produce of most
of the continuous barley plots, and also to determine the
amounts of dry matter and of ash, and to preserve the
ashes; though, as above suggested, it is a question
whether, or when, the sampling from some plots
may be discontinued. But here, as in the case of the
wheat, it is to be borne in mind that the crop history
is unique, and that it is desirable to have the means of
reference and selection for the consideration of points
other than those which present knowledge and require-
ment may suggest.
3. The Soils of the Continuous Barley Plots.
The experiments were commenced in 1852, but the
first soil samples were taken in 1868, and then only
from 4 selected plots. Samples were taken at 4 places
on each plot, and in each case to depths of 3 times
9 inches, or to a total depth of 27 inches. For each
depth, a mixture was made from the samples from the
B 2
20
4 places, and in these mixtures the total nitrogen has
been determined by soda-lime.
The same difficulty arose in the application of the
results relating to the subsoils, as in the case of the
wheat field subsoils, owing to the natural irregularity
in composition independently of the special history
of the plots ; so that only some of the results relating
to the surface soils have been published (No. 60,
p. 39, 1882).
In 1882, the soils of 26 of the 29 barley plots were
sampled, in most cases at 4 or at 3 places, but in a few
at only 2 places, on each plot, and in each case to the
depth of 3 times 9 inches, or 27 inches in all. A por-
tion of each individual sample is preserved, but mixtures
were also made representing respectively each of the 3
depths of each plot. Determinations of nitrogen by
soda-lime have been made in the first depth mixtures
for each of the plots, and in the mixtures of the second
and of the third depth for most of the plots. The
carbon has been determined in all the first depth mix-
tures, and in a few of those for the other depths.
Chlorine has been determined in some cases, and the
nitrogen as nitric acid at the 3 depths on most of the
plots. All the nitrogen as nitric acid results have been
published and discussed in No. 64, pp. 28-33, 1883.
Some illustrations have been given from the results as
to the total nitrogen in the surface soils, but none as to
that in the subsoils, nor as yet have any of the carbon
or chlorine results been published in detail ; but a
reference to the carbon results is given in No. 68>
p. 24.
If the exigencies of other work permit, it would be
desirable to sample the barley soils again after the
removal of the fortieth crop (ra 1891), that is after the
removal of 10 crops since the last sampling; and, as in
the case of the wheat field soils, the samples should be
taken in most cases to the depth of at least 8 times
9 inches, and in some to 12 times 9 inches; to the
greater depth more especially for the determination of
nitric acid, and perhaps of chlorine.
21
III. THE CONTINUOUS GKOWTH OF LEGUMINOUS
CROPS.
i
1. In Hoosfield.
It is a well-established fact in practical agriculture
in this country, indeed, in most other countries also,
that on only a few soils can a good crop of red clover
be obtained, even in rotation, so frequently as once in
4 years, and it is more frequently only grown once in 8
years.
Experiments on the growth of red clover, without
manure, and with different manures, were commenced
in Hoosfield in 1848-49, and continued up to 1877
inclusive ; that is, for a period of nearly 30 years. A
chronological account of the experiments, with some
reference to the manures employed, and to the crops
obtained, is annually given in the "Memoranda," but
the general results may be briefly stated as follows.
In the first year, 1849, heavy crops were obtained on
all the plots, and especially with mineral, but without
nitrogenous manures ; although, compared with crops of
the Gramineous and other families, red clover, as well
as other Leguminous crops, accumulate a very large
amount cf nitrogen over a given area.
Much smaller crops were obtained in 1851 and 1852,
but since that time nothing like a fair crop has been
grown on this ordinary arable land. Indeed, on the
greater part of the land, clover was sown 12 times in
the 30 years, 1848-77, and more frequently alone
than with a corn crop : but in 8 out of the last 10
trials the plant died off in the winter and spring suc-
ceeding the sowing of the seed.
The experiments were discussed up to date (1860),
in No. 13 ; and again in 1871, in No. 32 ; and the
subsequent history has been given in the " Memoranda"
22
as above referred to. Further, a summary of the yield
of nitrogen has been given and discussed in No. 77, and
more details, both as to produce and yield of nitrogen,
are given in No. 81.
After the failure of the clover, the land was devoted,
in 1878, to the growth of fourteen different plants of the
same, that is the Leguminous family, in order to ascertain
whether, among those having different habits of growth,
and especially different character and range of roots,
some could be grown successfully for a longer time,
and would yield more produce, containing more nitrogen,
as well as other constituents, according to their
characters in these respects.
A description, and a brief reference to the results, of
these experiments, will be found in the " Memoranda ;"
and the results, so far as their yield of nitrogen is
concerned, have been discussed in the paper in the
" Philosophical Transactions," numbered 77 in the list ;
and further results are given in No. 81.
The general result is, that very much more nitrogen
has been yielded on this clover-exhausted land, in some
of the other Leguminous plants, than in red clover
itself. Thus, whilst red clover yielded over 5 years
of the 8, 1878-85, when there was any crop, an aver-
age of only 22 Ibs. of nitrogen per acre per annum, and
over the 8 years only 14 Ibs., even the weakly growing
white clover, which, however, had not been grown on
the land for very many years, gave over 6 years of
growth an average of 47 Ibs., and over 10 years of
28 Ibs. ; Vicia sativa gave, over 3 years 120 Ibs., and
over 11 years 77 Ibs. ; Melilotus'leucantha gave, in one
year 130 Ibs., in another 145 Ibs., and over 11 years
62 Ibs. ; and lastly, the deep and powerfully rooting
Medicago sativa. gave, in 1 year 337 Ibs., in another
270 Ibs., in another 247 Ibs., and over 9 years an
average of 166 Ibs. of nitrogen per acre per annum.
It has been decided to consolidate these experiments ;
in some cases excluding, and in some transferring to
another plot, plants which have already more or less
failed ; and, in most if not all cases, allotting two lands
23
instead of only one to each description of plant still
kept under experiment. The number of different
plants will thus be reduced from 14 as originally, to 8
or to only 7. The plan will, however, not be fully
developed until 1892, or perhaps a year later.
The samples of produce taken will probably not be
much, if at all, reduced, at any rate for some years, as
an essential point of interest in the experiments is, to
estimate the yield of nitrogen over a given area, by the
different descriptions of plant, with their different
habits of growth, root-range, &c.
The Soils of the Hoosfield Leguminous Crop Plots.
The very remarkable results obtained in these
experiments led to the sampling of the soils of some
of the plots to a considerable depth in fact, to
a greater depth than had been adopted in the case
of any of the other experimental fields. In March
1881, samples were taken in 5 places on the land
where the clover had previously grown, and where
no nitrogenous manure had been applied from the com-
mencement, and in each case to the depth of 3 times
9 inches, or 27 inches in all. At the same time, similar
samples were taken from the immediately adjoining
land which had been devoted to the growth of the
Gramineous crop wheat, alternated with fallow, with-
out any manure, for almost exactly the same period
(nearly 30 years), during which the trials with red
clover had been made.
In July 1882, after the removal of the crops,
samples were taken from the Trifolium repens, and the
Melilotus leucantha plots, in each case to the depth
of 6 times 9 inches, or in all to 54 inches.
In July 1883, samples were taken from the wheat-
fallow, the Trifolium repens, and 2 Vicia sativa plots,
now in each case to the depth of 12 times 9 inches, or
108 inches.
24
Lastly, in July-August 1885, samples were taken
rom the wheat-fallow, the Trifoliurn repens, the
Melilotus leucantha, and the Medicago sativa, plots ;
again in each case to the depth of 12 times 9 inches, or
108 inches.
It was in the case of these Leguminous plant plots,
and, for comparison, in that of the alternate wheat and
fallow plots, that samples were first taken to so great a
depth as 12 times 9 inches; and here the natural
unevenness of the subsoils, as observed in other fields
to a less depth, was extremely marked. Nevertheless,
the determinations of nitrogen as nitric acid at the
different depths, on the plots where the different plants
had grown, gave results of very great interest. The
general result was, that less nitrogen as nitric acid
remained in the land to a given depth, the greater the
quantity of nitrogen removed in the crops. In illustra-
tion it may be stated that, after the Vicia sativa had,
over a series of years, yielded much more nitrogen in
crops than Trifoliuin repeus, the Trifoliurn repens soil
was estimated to contain per acre to the depth of 12
times 9 inches, or 9 feet, about 146 Ibs. of nitrogen as
nitric acid ; whilst the Vicia sativa soil indicated, in
one case only 64, and in another about 55 Ibs. ; and
again, after Medicago sativa had, for some years, yielded
very much more nitrogen than Trifolium repens, the
soil of the latter contained more than 100 Ibs. of
nitrogen as nitric acid, but that of the Medicago sativa
less than 20 Ibs.
A study of the results led to the conclusion, that
each of the Leguminous crops had taken up nitrogen as
nitric acid from the soil and subsoil, and that the plants
which had the greatest root-range had so taken up the
most. But, at any rate in the case of the Medicago
sativa, the figures did not justify the conclusion that
the whole of its nitrogen had been so derived. Assum-
ing that it were not, it is obvious that the deep-rooted
plant had either taken up combined nitrogen from the
subsoil in some other form, or that free nitrogen had,
in some way, been brought under contribution ; or
1'.-.
l>rrhaps that each of these sources had contributed
more or less to the result.
Owing to the uneven character of the subsoils which
has been referred to, it is impossible to determine by
the direct or statistical method, whether, or to what
extent, the subsoil has lost nitrogen. It is, as has been
intimated, in regard to these Leguminous plant- plots,
and to the comparison of the condition of the nitrogen in
their subsoils with that in Gramineous crop subsoils, and
especially in the subsoils of the immediately adjoining
urimanured wheat-fallow plots, that the investigation,
and settlement, of an indirect method, as suggested at
pp. 14-16, would be of very great interest and importance.
The samples of subsoil already collected from the
Leguminous plant, and wheat-fallow plots, would, if any
such indirect method were established, probably yield
very fruitful results ; but, as time goes on, the character
of the subsoils in the two cases will, on the supposition
in question, become more and more distinct.
It need only be added in regard to these Leguminous
plant experiments in Hoosfield, that so far as the sur-
face soils are concerned, the determinations of nitrogen
by soda lime, and so far as both the surface and the
subsoils are concerned, the determinations of nitrogen
as nitric acid, have already been published and discussed
in our paper in the " Philosophical Transactions,"
numbered 77 in the list ; and later results are given in
No. 81.
It is a question for consideration when, and from
which plots, samples of these leguminous plant soils
should be again taken and investigated.
THE CONTINUOUS GKOWTH OF LEGUMINOUS CROPS.
2. In Gfeescruft Field.
This field was devoted to the growth of the Legumin-
ous crop beans for a period of 32 years ; but owing
to frequent failures of the crop, wheat was once taken,
26
and the land was several times left fallow, during the
period.
At the conclusion of the 32 years (in 1878), the land
was left fallow until September 1882, when it was sown
with grass-seeds, which, however, failed in the winter, and
then another Leguminous crop red clover which had
not been grown on the same land for very many years,
was sown (with barley), and it yielded, on this so to speak
bean-exhausted land, large crops ; which, within a period
of about 2 years, accumulated (including a little in the
barley) more than 300 Ibs. of nitrogen per acre in the
removed crops ; whilst, at the same time, the surface
soil became determinably richer in nitrogen.
This result was obtained, where another Leguminous
crop had yielded smaller and smaller crops, where the
surface soil was very poor in total nitrogen, very poor
in nitrogenous crop residue for nitrification, and the
subsoil was, to a considerable depth (72 inches), very
poor in 'ready-formed nitric acid. Here, again, then,
satisfactory explanation as to the source of the nitrogen
of the crop fails, in defect of evidence as to whether, or
in what degree, the subsoil has contributed to the result.
In view, however, of recent results, showing the fixation
of free nitrogen as a coincident of the development of
the so-called " nodules " on the roots of leguminous
plants, there can be little doubt that at any rate some
of the nitrogen accumulated by the clover after the
beans in Geescroft Field, and also of that obtained by
the lucerne, and other leguminosse, grown after the
failure of red clover in Hoosfield, was due to the fixation
of free nitrogen under such conditions. See Nos. 81,
82, and 84, in the list.
As in the case of other crops, samples of both bean-
corn and bean-straw, have been preserved. In all, the
dry matter and the ash have been determined ; and, in
the case of the produce of some plots in a number of
individual years, and of some in " mixed-year " samples,
the nitrogen has been determined. Complete analyses
have also been made of 34 corn and 34 straw ashes,
representing in each case " mixed - year " samples,
27
corresponding to those in which nitrogen has been
determined.
Soil samples were taken from a selection of plots,
in 1857 to a depth of 9 inches, in 1865 to the depth of
3 times 9, or 27 inches, in 1874 to the depth of 9 inches,
in 1883 to the depth of 8 times 9 inches, and in 1885
to the depth of 9 inches only. The nitrogen by soda-
lime has been determined, in mixed samples for each
selected plot and depth, and in some individual
samples ; and in some the nitrogen as nitric acid has
also been determined.
Some of the results have been given in No. 67 ; but
more, though still only in summary, in their bearing
on the question of the sources of the nitrogen of vege-
tation, in the paper in the " Philosophical Transactions,"
numbered 77 in the list, The results have, however,
been published more fully, so far as they relate to
the amounts of produce of the bean and clover crops,
and to the nitrogen in them, in No. 81.
It may be added, that after the removal of the clover
crops, and the final soil sampling in 1885, the portion
of the field that had been under continuous bean crops
was fenced off to exclude cattle from it, a'iid it has been
left uncultivated ever since. A luxuriant growth of
grasses, and other herbage, soon established itself, and
this has been left to seed, with the object of ascertain-
ing to what extent the soil will acquire fertility under
the influence of the undisturbed natural perennial vege-
tation. It is doubtful whether it will be worth while to
sample the soil at the end of 10 years, that is in 1895,
and it may be desirable to let the experiment go on for
at least 20 years, and perhaps longer; but the soil
should certainly be sampled at the expiration of
20 years, and again at the termination of the experi-
ment if it be continued longer. It should be observed
that this portion of land has not been conveyed to the
Trustees, but Sir J. B. Lawes leaves a memorandum
expressing his wish that the land shall remain at the
disposal of the Committee so long as they desire to
carry on the experiment.
28
THE CONTINUOUS GKOWTH OF LEGUMINOUS CHOPS.
3. In rich Garden soil.
Some account of this experiment is given in the
" Memoranda" and the results liave frequently been
discussed more or less fully in various papers as
for example in Nos. 38, 51, and 60 ; but they are given
in more detail in No. 81.
The experiment was commenced in 1854, and is still
in progress, so that this, 1891, is the 38th season of the
growth of red clover year after year on rich garden
soil. The plots are very small, so that estimates of the
amounts per acre, of the produce, or of the nitrogen in
it, can only be approximate. The crops are, however,
always weighed ; samples are always taken for the de-
termination of dry matter, ash, and sometimes nitrogen ;
and it is estimated that the amounts of produce were,
in the early years much more than, over the whole
period also more, and, even in many of the later years
as much as, is usually obtained on ordinary arable land
only once in 4, 6, or 8 years ; and the yields of nitrogen
in the crops are, accordingly, correspondingly large.
Samples of the soil have also occasionally been taken,
and the results point to the conclusion that much of
the nitrogen of the clover crops has been derived from
the soil.
The plot of land upon which these experiments are
conducted, is not transferred to the Trustees, but it is
very desirable that they should be continued until
decided failure is manifested. The crops should always
be weighed and sampled, as heretofore ; the dry matter
at once determined for the estimation of the crop ; the
ash also determined ; and samples reserved for " mixed-
crop " and " mixed-year " samples, for nitrogen deter-
minations, with a view to the estimation of the yield of
nitrogen in the produce. The soils were last sampled
in 1879, and it would be of interest again to take
samples and determine the nitrogen in them, before
20
long. Owing, however, to the smallness of the plots, it
is undesirable to remove samples frequently; and
whether or not any be taken intermediately, they
should certainly be taken to some depth, whenever it
may be decided to terminate the experiment.
IV. EXPERIMENTS ON THE CONTINUOUS GROWTH OF
ROOT-CROPS, IN BARNFIELD COMMON TURNIPS,
SWEDISH TURNIPS, SUGAR BEET, AND MANGEL
WURZEL.
1. The Field Results, and the Composition of the Crops.
These experiments were commenced in 1843, and are
still in progress; so that this season, 1891, will be the
49 ch of their continuance. There was, however, a break
after the first 10 years, when, for 3 years in succession,
barley was grown, without any manure, over all the
plots, in order as far as possible to equalize their con-
dition, due to the previous various manuring, with a
view to a more systematic arrangement. Thus, the
different crops have already been grown as follows :
Norfolk White Turnips . . 6 years 1843-48
Swedish Turnips . . 4 years 1849-52
(Barley without manure) . . 3 years 1853-55
Swedish Turnips .. .. 15 years 1856-70
Sugar-beet . . . . . . 5 years 1871-7")
Mangel Wurzel .. .. 15 years 1876-90
Since the re-arrangement in 1856, there have been
about 40 plots, without manure or with different
manures. The roots and leaves are always 'weighed.
A sample of the roots is taken from each plot, and of
the leaves from a selection of plots. The dry matter
and ash are always determined, and partially dried
samples preserved for determinations of nitrogen, &c.
In each of the 5 years of sugar-beet, the sugar was also
determined by polariscope, in 2 of the years in the
produce of 40 plots, in 1 year in that of 35 plots, and
30
in 2 years in that of 30 plots. The sugar was also
determined in the produce of the first 5 years of
mangel wurzel in the first year in 20 samples, and in
each of the succeeding 4 years in 31 samples.
The results of the first 3 years of the continuous
growth of root-crops 1843, 4, and 5 were published,
and discussed pretty fully, both as to the amounts of
produce, and to its composition, according to the
manures employed, in 1847, in No. 2 in the list.
The field results for the 26 years, 1845-70, are sum-
marised in the " Memoranda."
For each of the 5 years of sugar-beet, 1871-75, the
produce of both roots and leaves of each plot, the per-
centages of dry matter and ash in the roots of each
plot, of sugar in those of most, and of nitrogen in those
of some of the plots, are given in the " Memoranda?'
For each of the 15 years of mangel wurzel, 1876-90,
the produce of both roots and leaves of each plot is
given, and the percentages of dry matter and ash in
the roots of each plot, that of sugar in those of
most in the first 5 years, and that of nitrogen in
the roots of a selection of plots each year, are given in
the " Memoranda"
The results, both as to produce and composition of
the various root-crops have been discussed in my
Oxford Lectures, the substance of which it is arranged
shall be published ; and a summary of the results was
given in No. 76, in 1887.
Analyses have also been made of the ash of the juice
of 32 different samples of the sugar-beet.
The present year, 1891, is the sixteenth in succession
of mangel wurzel ; and unless the crop should signally
fail from other than obviously temporary season con-
ditions, it will be desirable to continue the experiments
with mangels, which are among the most important of
our root-crops, for a fourth period of 5 years, that is
until after the removal of the twentieth crop in 1895.
After that time, or whenever a change is made, it would
be desirable to grow say 3 crops of barley without
manure, clover being sown with the third barley- crop,
31
and wheat after the removal of the clover, also without
manure; in order to gauge, and as far as possible
equalise, the condition of the different plots. Experi-
ments might then he re-commenced with mangels, or
with some other root-crop.
It is undesirable to reduce the number of samples
taken of mangel roots, and mangel leaves, as long as the
present arrangement of plots and manuring is continued,
as it is very important to keep up the chemical statistics
of the crops, and especially the nitrogen statistics. But,
if it were considered necessary to reduce the sampling,
the most important to continue are Nos. 4, 5, and 6, of
each of the five series ; and of these the leaves, as well
as the roots, should be sampled as at present. Although
the leaves of the crop are left on the land, they are
always weighed, and it is very important to have the
means of estimating the amount of constituents
accumulated in the leaves, and how much, therefore, of
the constituents of the manure and of the crop, remains
as only manure again, under the different conditions as
to manuring, and the coincident different conditions of
development and maturation.
With a view to the elucidation of the points here
referred to, as well as of others, complete analyses of
mangel-root-ash, and of mangel-leaf-ash, are specially
needed in "mixed-year" samples, for the 5 years
1876-80 (or for the 6 years 1878-83 see "Root-crop"
Lecture, No. 76, p. 25), and also for the 5 years
1886-90, or at least for one of these periods, for the
plots as under :
Series " 0," Plot 4, Plot 5, Plot 6.
Series " N,"
Series " A," ,.
Series " AC,"
Series " C,"
2. The Soils of the Hoot-crop Plots.
Samples of the soil of the root-crop land were col-
lected in 1870, from 35 of the plots, at 4 places on
32
each, and in each case to the depth of 3 times 9 inches,
or in all 27 inches. The nitrogen has been determined
in the mixed sample from the 4 holes, for each depth,
for each of the 35 plots.
The results relating to some of the surface soils only,
have as yet been published (No. 67) ; and they are of
much interest as showing that, under the influence of
the growth without nitrogenous manure, of these
reputed restorative crops, the surface soil is to a greater
extent exhausted of its available nitrogen than by the
growth of any of the other experimental crops, even
than by the continuous growth of the cereals.
The results relating to the subsoils are subject to
the same observations as those obtained with other sub-
soils, and have not been published.
The soils of the root-crop plots should be again
sampled, both for total nitrogen and for nitric acid
determinations, whenever the growth of mangel-wurzel
is discontinued, and again after the 5 years of the
gauge-cropping, as above proposed.
V. THE CONTINUOUS GEOWTH OF POTATOES IN Hoos-
FIELD.
1. The Field Results.
These experiments were commenced in 1876, and are
still in progress, so that the crop of the present season,
1891, is the sixteenth in succession on the same land.
The series comprises 10 plots. The description and
amounts of the manures used (if any), and the amounts
of produce, each year, are given in the "Memoranda."
2. The Composition of the Crops.
Hitherto, samples have been taken of the " good," of
the " small," and of the diseased potatoes, of each plot,
33
each year. Each year determinations of the specific
gravity of the " good " tubers, and of the percentages
in them, of dry matter, ash, and nitrogen, have been
made, and the results are annually given in the
" Memoranda." In the " small " potatoes also, the
specific gravity, and the dry matter, have always been
determined; in some years the ash, and in one year
the nitrogen was also determined ; but nitrogen might
suitably be determined in " mixed-year " samples only.
In the diseased potatoes the dry matter is determined
and sometimes the ash.
The dry matter, the sugar, the nitrogen, and the
ash have, in selected cases, been determined in the
expressed juice of the tubers. In some cases the
amount of the nitrogen existing as albuminoids has
been determined ; and in some complete analyses of
the ash, both of the whole tubers and of the juice,
have been made. In a considerable number of cases,
somewhat similar methods of examination to those
adopted in the case of the sound tubers, have been
applied to the still white or incipiently diseased, and
to the separated discoloured portions, of diseased
potatoes. These various results are briefly referred to
in the heading to the Tables of composition of the
potatoes, in the " Memoranda;" and are of considerable
importance.
The results of the experiments on Potatoes, both
those obtained in the field and in the laboratory, have
been pretty fully discussed in my Oxford Lectures ;
and a resume has been given in No. 78, 1888.
It seems desirable that the sampling of the " good "
potatoes, and the determination of their specific gravity,
and of their percentages of dry matter, ash, and
nitrogen, should be continued so long as the field
experiments are maintained. But possibly the sampling
of the " small " and " diseased " potatoes, might be
discontinued after that of the crop of 1890, which is
the fifteenth of the experiments ; unless it should be
found desirable to follow up any special point in any
subsequent year,
VI. WHEAT ALTEENATED WITH FALLOW, IN HOOSFIELD.
1. The Field Eesults.
From 1851 up to the present time, 1891, one acre has
been devoted in Hoosfield to the growth of wheat in
alternation with fallow without any manure. This year,
1891, is, therefore, the 41st season of the experiment.
In the first year the whole acre was fallow, in the second
wheat, in the third fallow, and in the fourth wheat ; in
the fifth half fallow and half wheat, and this plan has
been followed ever since, that is, the crop and the fallow
have been alternated on the respective halves each
year.
A summary of the crop results is annually given in
the " Memoranda" and they are there compared with
those obtained in the growth of wheat year after year
on the same land, without manure, in the immediately
adjoining Broadbalk field.
There is only 1 sample of grain and 1 of straw taken
each year, and no reduction in the sampling, or in the
drying and burning, is recommended ; but " mixed-year "
(instead of individual year) samples, may be made for
nitrogen determinations.
2. The Soils of the Wheat-Fallow Plot.
Independently of the interest of the crop results as
such, the fact that the alternate wheat and fallow plot
is immediately adjoining the Leguminous crop plots in
the same field, and that from the commencement of the
experiments with clover on the Leguminous crop plots
the two sets of experiments, the one with a Gramineous
crop, and the other with Leguminous crops, have pro-
ceeded side by side for almost exactly the same period
of time, gives to the soil history of the alternate wheat
and fallow plot an especial interest. This point has
been referred to already when speaking of the Legumi-
nous crop plots, and, as intimated, the soils of the two
sets of plots have generally been sampled at the same
dates, and to the same depths, with a view to compara-
tive results. The results already obtained, especially so
far as the nitrogen as nitric acid is concerned, are of
much interest ; and, as has been said, the further com-
parative investigation of these adjoining Leguminous
and Gramineous crop soils and subsoils, promises, per-
haps, more fruitful results, than that of any of the other
Itothamsted experimental soils.
Samples of soil were taken from the wheat-fallow
plots at 5 places to the depth of 3 times 9, or 27 inches,
in 1881 ; from 4 places to the depth of 12 times 9 inches,
or 108 inches, in 1883 ; and from 3 places, also to the
depth of 108 inches, or 9 feet, in 1885. The results of
the determinations of nitrogen by soda-lime in the
surface soils, and those of nitrogen as nitric acid in both
surface and subsoils, have been given and discussed, in
more or less detail, in Nos. 62, 64, 67, 77, and 81 in
the list.
VII. EXPERIMENTS ON ROTATION, IN AGDELL FIELD.
1. The Field Results.
It will be observed that, in the case of each of the
field experiments hitherto considered, the plan has been
to grow the same crop year after year on the same land,
without manure, and by different descriptions of manure.
In those now to be described, various crops are grown
in an actual and typical course of rotation, namely, the
so-called four-course rotation, of turnips, barley, Legu-
minous crop or fallow, and wheat. The experiments
were commenced in 1848, and are still in progress, so
that the crop of the present year, 1891, is the 44th, and
the fourth of the eleventh course of 4 years.
One-third of the land has been unmanured from the
commencement, one-third has received mineral manure
only, and one-third a mixture of both mineral and nitro-
genous manure; the manures being applied once in
4 years only, that is for the turnips commencing each
course. From half of each of the 3 plots, the turnip-crops
c 2
(roots and leaves), are entirely removed, and on the other
half they are either consumed on the land by sheep, or
cut, spread, and ploughed in. All the other crops are
entirely removed from the land. Excepting in the first
course of 4 years, when clover was grown as the third
crop over the whole of each plot, in the third year one
half of each has grown a Leguminous crop (clover or
beans), and the other half has been left fallow.
Thus, each of the 3 differently manured plots is divided
into 2, so far as the treatment of the turnips is concerned,
so making 6 : and each of these is again subdivided in
the third year, one part growing a Leguminous crop, and
the other being fallow, thus making in all 12 plots.
The crop results of these 12 plots, in each of the 4.")
years now completed, are recorded in the " Memoranda ''
up to date.
2. The Composition of the Rotation Crops.
Each year samples of the roots and leaves, or the corn
and straw, or of the clover crops, are taken. Portions
of each are partially dried and preserved, for nitrogen or
other determinations ; and portions are fully dried, the
dry matter determined, and then burnt to ash, the ashes
being preserved.
Very many nitrogen determinations have been made
in the produce, sometimes in individual samples, some-
times in " mixed-plot" and sometimes in " mixed-year "
samples. Sixty complete ash-analyses have also been
made; chiefly in "mixed-plot" or in ''mixed-year'"
samples.
3. The Soils of the Rotation Plots.
In 1867, samples were taken from each of the 12
plots, at 4 places on each plot, and in each case to the
depth of 3 times 9 or 27 inches; and the nitrogen by
soda -lime has been determined in the mixed sample
from the four holes, for each plot, and for each
depth.
In 1874, samples were again taken from each plot, at
3 places on each, and in each case to the depth of 3
37
times 9 inches, or 27 inches. Nitrogen determinations
(by soda-lime) have been made in the mixed samples
from the 3 holes, in each case ; and the nitrogen as
nitric acid has been determined in the soils and subsoils
of 6 of the plots.
In the winter of 1883-84, samples were again taken
from each of the 12 plots, from 4 places on each plot ;
and in the case of 2 of the 4 holes only to the depth of
9 inches, but in that of the other 2, to the depth of 12
times 9 inches, or 108 inches in each case. Nitrogen
determinations have been made (by soda-lime), in the
surface soils, in the mixture from the 4 holes, in a mix-
ture from the 2nd and 3rd holes, and in that from the
1st and 4th holes ; also in the subsoils, at each of the
11 lower depths, in the mixture from the 2 holes in
each case. In the case of 4 of the 12 plots, the nitrogen
as nitric acid has been determined in the mixed sample
from the 2 holes, for each of the 12 depths ; and in the
case of each of the 12 plots, in the mixed samples of
the 12th depth ; also in a few individual cases. In a
few cases the chlorine was also determined.
In the case of these experiments on rotation, it is pre-
eminently essential to have the means of tracing the
chemical history of the plots, both so far as the crops,
and the soils, are concerned. To this end, it is desirable
to take samples for dry matter, ash, and nitrogen of the
roots and of the leaves, of each of the 12 plots when
under turnips ; of the corn and of the straw, of each of
the 12 plots when under barley ; of each cutting, of
each of the 6 plots, when under clover ; of the corn and
of the straw, of each of the 6 plots when under beans ;
and of the corn and of the straw, of each of the 12,
when under wheat. But, for actual determinations of
nitrogen, or for ash-analyses, "mixed-year" samples
and in some cases "mixed-crop" samples, can be
adopted.
It would, however, be undesirable to curtail the
system of collection and preservation of samples, until
the proposed systematic report on the Rotation
38
Experiments has been published; after which the
subject may be re-considered.
Soil samples should probably be again systematically
taken at the conclusion of the current rotation that is
in the autumn of 1891, after the removal of the wheat,
or, if not then, at the conclusion of the next rotation ;
for the determination of total nitrogen in the surface
soils, and of nitric acid, and perhaps chlorine, in the
subsoils to a considerable depth.
Independently of the numerical record of the crop-
results given in the " Memoranda " as above referred to,
and occasional illustrations drawn from them, or from
the analytical results, embodied in various papers, the
Rotation results as a whole have not been published.
They have, however, been arranged, studied, and pretty
fully discussed, in 8 of my Oxford Lectures. This dis-
cussion includes that of the Field results, the composi-
tion of the crops, and the soil results ; and, so far as
the composition of the crops is concerned, the results of
the 60 complete ash-analyses, as well as some others,
have been applied. The arrangement, study, and dis-
cussion herein involved, is supposed to provide the
basis for a systematic paper on the whole of the Rota-
tion results, both crop and analytical ; and it is believed
that such a paper will prove to be of great interest and
importance. It is not intended that any resume of this
discussion shall appear before the full paper is published.
Such a resume may, however, afterwards be given in the
series of my Cirencester Lectures ; and it is supposed
that the main results will also afterwards be given in
the proposed publication of the series of subjects
embodied in the Oxford Lectures.
VIII. THE EXPERIMENTS ON THE MIXED HERBAGE OF
PERMANENT GRASS-LAND. THE PARK.
1. The Field Results.
The majority of these experiments were commenced
in 1856, so that the present season, 1891., is the 36th
of their continuance; 4 plots (14, 15, 16, and 17) were,
however, only brought in in 1858, and 2 others (19 and
20) only in 1872. The total number of plots is now
20, but 3 of these have for many years been divided,
making in fact 23 plots in all. During the first 19
years, first crops only were removed as hay, the second
crops being either consumed by sheep on the land, or
cut and spread upon it. Since that time, second (and
sometimes third) crops have as a rule been cut ; some-
times removed as hay, and sometimes only cut and
spread on the land. Further particulars on these points
will be found in the paragraphs at the head of the
Table of manures and produce given in the "Memo-
randa,"
In the " Memoranda " there is annually recorded, the
manuring and produce of each plot in the immediately
preceding season, the average amounts of produce over
the first 10, the second 10, and the first 20 years, from
the commencement, when first crops only were removed ;
also the average amounts of the first crops, the second
crops, and the total, over the succeeding years. The
description of manures given to the left of the columns,
together with the heading and the foot-notes, gives a
complete account of the manuring of each plot from the
commencement. There is also given a statement of the
special treatment of portions of the plots in recent
years, by the application of chalk, or of lime, or of both.
2. The Composition, Botanical and Chemical, of the
Crops.
4 sample of the produce of each plot, and of each
crop if more than one, is taken each year. A portion of
this is preserved for nitrogen determinations, or other
chemical examination, and 2 portions are dried at 100,
the dry matter determined, and then burnt to ash, the
ashes being preserved.
Nitrogen determinations have been made in the
mixed herbage of most of the plots, in most of the
years ; in a few cases in mixed year samples only ; but,
40
in .recent years, in the chalked and limed portions,
respectively, of the plots. In the case of selected plots,
generally 8 or 9, in 4 years, and once in second as well
as first crops, the dry matter, ash, and nitrogen have
been determined in the separated Gramineous, the
separated Leguminous, and the separated miscellaneous
herbage, of the mixed produce.
In selected cases, the " woody-fibre" in a given con-
dition of induration, has been determined; and in
selected cases also, the proportion of the total nitrogen
existing as albuminoids has been determined.
Complete analyses have been made of 145 selected
ashes, most of "mixed year" samples, some of second as
well as first crops, and some of the separated Gramineous,
Leguminous, and miscellaneous herbage.
Besides the above-enumerated samples taken for
chemical investigation, very numerous samples have
been taken for determining the botanical composition of
the herbage. Thus, in each of the years 1862, 1867,
1872, and 1877, 20 or more samples were taken, and
submitted to complete botanical separation ; and for
each of these separations the aid of a special assistant
was obtained ; but the work involved that of one of the
Eothamsted staff, and a number of boys also. In
1871, 1874, and 1876, a few samples were taken for
partial separation only that is into total Gramineous,
total Leguminous, and total miscellaneous species ; and
in 1875, and in each year since 1877, from about 10 to
20 or more samples have been taken for such partial
separation ; all the partial separations being conducted
by one of the Eothamsted staff, assisted by a number of
boys. In some cases samples from second as well as
first crops have been operated upon.
3. The Soils of the Mixed Herbage Plots.
In the summer of 1870, which was a period of
drought, very variously affecting the herbage of the
different plots, samples were taken from 3 of the plo.ts,
in each case to the depth of 6 times 9 inches, or to a
41
depth of 54 inches. The special object was to
determine the difference in the amounts of water at the
different depths of the respective plots, with their very
varying characters of herbage. In all the samples the
nitrogen was also determined.
In 1876, samples were taken from 22 plots, at 3
places on each plot, in each case to the depth of 6 times
9, or 54 inches. Nitrogen determinations (by soda-lime)
have been made in the mixed sample from the 3 holes
in the case of each plot, and of each depth. Some deter-
minations have also been made in single samples. In
many cases the carbon has also been determined, and
sometimes both by the combustion and the chromic acid
method. In a few cases also the nitrogen as nitric
acid was determined.
In 1878, samples were taken from 4 selected plots,
from 3 places on each, but to the depth of 9 inches
only. In the single as well as in the mixed samples
from the 3 holes on each plot, the nitrogen has
been determined; the carbon has been determined in
the mixed samples, and in one case the nitrogen as
nitric acid.
In 1885, samples were taken from 2 selected plots,
from 2 places on each, but to the depth of 9 inches
only. In the samples from each of the 2 holes the
nitrogen has been determined.
In 1886, 12 samples were taken, 5 from one plot,
and 7 from another, to the depth of 9 inches only,
specially with the view of tracing the connection be-
tween the character of the herbage, and the amount of
nitrogen in the soils, and the nitrogen was accordingly
determined in them.
Independently of the annual record of the crop
results in the " Memoranda " the results of the grass
experiments were reported upon in No. 12, 1858-59,
and in No. 19, 1863 ; botanical and chemical, as well as
crop results being considered. But the results for the
first 20 years (and in some cases longer), have been much
more fully discussed in two papers in the " Philosophical
42
Transactions" No. 50 (1880), and No. 61 (1882).
The first of these papers (Part I) treated specially of
" The Agricultural Results" but involved the use of
some of the chemical and some of the botanical data
also. In the second paper (Part II) " The Botanical
Results " were given and discussed in detail. In these
papers it is stated that the Chemical Results will be
given in a Third Part. This Third Part has not yet
been published, but the chemical results have been to a
great extent arranged, studied, and discussed, so far as
was suitable, in my Oxford Lectures ; and it is assumed
that this arrangement, study, and discussion, will serve
as a basis of a systematic paper constituting "Part III,
The Chemical Results." It may be added that the dis-
cussion in question includes that of the results of the
numerous complete ash-analyses above referred to.
Although Parts I and II related mainly to the results
of the first 20 years, Part III, which it is hoped will
soon be ready for publication, must necessarily include
those of later date. It will, indeed, probably include
many results up to 1889, and some to 1890, inclusive.
From the foregoing account it will be seen that
these experiments on the mixed herbage of perma-
nent grass land, involve a very great deal of work ;
they do, in fact, involve more than any other equal
area of the Field experiments. In the field there are,
it is true, no mechanical operations, as in the case of
the arable land. But from the complexity of the
produce, and the great difference in composition, both
botanical and chemical, of the herbage of the different
plots, the sampling of the crops, the preparation and
treatment of the samples, and the analytical work,
both botanical and chemical, take up much time, and
employ much labour.
The sampling of the soils, the preparation of the
samples, and the determinations of nitrogen, carbon,
and nitric acid, in them, have also occupied much time.
Until the whole of the results for Part III have
been arranged, and fully studied, it is impossible to
decide whether any, or what reduction, in the sampling
4:;
of the crops, and of the soils, arid in the treatment of
the samples, can be recommended. It is possible that
some curtailment may be at once admissible ; or it may
be considered desirable to continue the work on pre-
sent lines, at any rate until after the conclusion of the
second period of 20 years of the experiments, in 1895.
It will certainly then be desirable to re-sample the
soils of most, if not all, the plots ; to a limited depth
for tha determination of nitrogen by soda-lime, and in
selected cases of carbon; also in selected cases, to a
considerable depth for the determination of nitric acid,
and perhaps of chlorine, and some other constituents.
If not before, the system of sampling the crops, both
for chemical and for botanical investigation, might at
any rate then be fully reconsidered.
Thus far I have given an account of the history and
present position, of all those of the Eothamsted Field
Experiments which are conducted on the areas of land
conveyed to the Trustees ; both in regard to the crop
results, and to the Laboratory investigations connected
with them. I have also described some conducted
with Leguminous crops in Geescroft Field, which is
not included in the areas set apart for the continuance
of the experiments. I should, however, briefly refer to
some other experiments that have been made in that
field, and also to some conducted in other fields which
are not set apart for future experiments.
IX. EXPERIMENTS ON OATS, IN GEESCROFT FIELD.
The whole of Geescroft Field was devoted to experi-
ments with various Leguminous crops in 1847. The
portion on which those with oats were afterwards
made, grew clover in 1847 and 1848, beans for 11
years, 1849-59, and then, during 9 years, 1860-68, the
land was twice left fallow, grew five crops of wheat
without manure, one crop of beans with farmyard
manure, and one without manure. The first experi-
mental Oat crop was grown in 1869, and the last in
1878, after which, owing to the wetness and the foul-
ness of the land, it was left fallow for several years,
and then the experiment was finally discontinued. The
results obtained were, however, sufficient to show the
general similarity in manurial requirement of oats and
the other cereals, wheat and barley ; and although there
are obviously points of difference also that it would
have been of interest further to investigate, the diffi-
culty of keeping such crops clean when grown year
after year on the same land, proved a sufficient obstacle
to the continuance of the experiment.
The numerical results of the Field experiments are
recorded in the "Memoranda." They have not been
systematically discussed in any separate paper ; but
attention has been called to their more important
indications in my Oxford Lectures.
Samples of the produce of each plot, both grain and
straw, were taken each year, and the dry matter and
ash determined in them. In the case of 3 of the
plots, the nitrogen also has been determined, in pro-
portionally mixed samples of the produce (of grain and
straw separately), of the first 4 years, 1869-72.
Soil samples were also taken, to the depth of
9 inches only, from 2 of the plots in 1874, which was
the sixth year of the experiment; and in these the
nitrogen (by soda-lime) has been determined.
X. EXPERIMENTS ON THE ALTEKNATION OF WHEAT AND
BEANS, IN GEESCKOFT FIELD.
A portion of the Field, comprising 10 plots, on which
peas had been grown for 4 years, 1847-50, was then
devoted to the growth of beans and wheat alternately ;
the respective plots being differently manured for the
beans, but unmanured for the succeeding wheat. The
experiment was continued without a break for 16 years ;
and for 12 years more somewhat irregularly, owing to
the wetness and foulness of the land ; and, for the same
45
reasons, it was finally abandoned after the bean crop of
1878.
The numerical results of the Field experiments
have net been published; but a general statement is
given in the "Memoranda" As there stated, the
remarkable result was obtained that, without nitrogen-
ous manure, nearly as much wheat, and nearly as much
nitrogen, were yielded in 8 crops of wheat grown in
alternation with the highly nitrogenous beans, as in 10
crops of wheat grown consecutively over the same
seasons, in another field ; and also nearly as much as
were obtained in a third field, in 8 crops of wheat
alternated with bare fallow. Further, the yield of
nitrogen in the 8 intermediate crops of beans was, with-
out manure not much less, and with mineral manure
more, than in the wheat alternated with them.
Thus, as compared with the effects of bare fallow
on the yield of nitrogen over a given area, that
obtained in the beans was almost entirely clear gain ;
and the results as a whole afford a striking illustra-
tion of the influence of the interposition of Leguminous
with Gramineous crops, in augmenting the yield of
nitrogen over a given area of land.
Samples, of both corn and straw, of both the wheat
and the beans, were always taken, the percentages of
dry matter and of ash determined in them, and the
ashes preserved. In selected cases, in the earlier years
of the experiment, the nitrogen was also determined, in
the corn and in the straw, of both crops.
In the autumn of 1857, after the removal of the
fourth crop of wheat, surface soil-samples, to the depth
of 9 inches, were taken from 4 places on each of 4
of the 10 plots ; and at the same time similar samples
were taken from 4 plots in the same field, respectively
somewhat corresponding in manurial history, but where
the Leguminous crop, beans, had been grown year after
year without the interposition of wheat. Again, in the
autumn of 1865, after the removal of the 8th crop of
wheat (alternated with beans), samples were taken from
the same 4 plots, and also from the 4 corresponding
continuous bean plots ; this time to the depth of
3 times 9 inches, or in all to 27 inches. In all these
samples the nitrogen (by soda-lime), has been deter-
mined, but none of the results have yet been published.
They will probably be most appropriately discussed in
connection with the subject of the experiments with
Leguminous crops taken as a whole.
In addition to the above, surface-soil samples were
taken in 1883, 5 years after the discontinuance of the
experiments both with beans grown continuously, and
with beans and wheat grown in alternation, and some
were also taken in 1885. In all the nitrogen by soda-
lime, and in some the nitrogen as nitric acid, has been
determined; and a selection of the results has been
published. (See No. 67, p. 404; No. 77, p. 21; and
No. 81, p. 29.)
XI. EXPERIMENTS ON BARLEY AND CLOVEK, IN LITTLE
HOOSFIELD.
These experiments are of considerable interest, but
they also have been conducted in a field not set apart
for continued investigation.
The field had grown 5 corn crops in succession
(1 Wheat, 1 Oats, and 3 Barley), the first without any
manure, and the last 4 with artificial mineral and nitro-
genous manures, but without any farmyard or other
organic manure, up to 1871 inclusive. In 1872 barley
was again grown, with artificial mineral and nitrogenous
manures ; but now the field was divided, and clover sown
with the barley on one half. In 3873 barley was again
grown on the one half, but clover on the other. The
barley yielded 37'3 Ibs. of nitrogen per acre, but the
three cuttings of clover contained. 151'3 Ibs. In the
next year, 1874, barley was grown on both portions, and
on the one where barley had, in the previous year, yielded
37'3 Ibs. of nitrogen, it now yielded 391 Ibs. ; but, on
the portion where clover had yielded 151 '3 Ibs. of
nitrogen, the barley succeeding it now yielded 6 9 - 4.
That is to say, the barley yielded 30 '3 Ibs. more nitrogen
47
after the removal of 151*9 Ibs. in clover, than after
the removal of only 37'3 Ibs. in barley.
In October, 1873, after the removal of the barley and
the clover, samples of soil were taken from 10 places on
each of the two portions, in each case to the depth
of 3 times 9 inches, or 27 inches. Nitrogen was deter-
mined, by soda lime, in the samples from each depth, of
4 of the individual holes separately, and in the mix-
ture of the 4; also for each depth, in a mixture of
the samples from the other 6 places. In the first-depth
samples the carbon was also determined.
The results showed that the surface soil of the clover
land, which had yielded so much more nitrogen in the
crops, was nevertheless determinably richer in nitrogen
than that of the barley land which had yielded so much
less. This was the case, notwithstanding all visible
vegetable debris had first been removed from the
samples. It was further found, that the above and
underground vegetable residue, picked from the clover-
land samples, was much more in quantity, and contained
much more nitrogen, than that from the barley-land
samples.
In 1874 and 1875, barley only was sown over both
portions. In 1876 barley was again sown over the
whole of the land, but with clover as well on the por-
tions where it had been grown in 1873 ; but the plant
failed in the winter, and gave no crop in 1877. In
1877 barley was again sown over the whole, and this
time with clover on half of the previously clover
portion, and on half the previously only barley portion.
In the autumn of 1877, soil samples were again taken,
this time from four places on each of the four differently
cropped portions, and in each case to the depth of
times 9 inches, or 54 inches. Nitrogen, by soda-lime,
has been determined in the mixture from the four holes
on each plot, for each depth separately. Nitric acid
has been determined, at each depth, in the mixture
from the four holes in the case of two of the four plots,
and the carbon has been determined in the first depth
samples.
48
The determinations of nitrogen by soda-lime in the
surface soils consistently show, as before, a higher per-
centage where clover had grown than where only barley
had grown. As in the case of the subsoils from other fields,
the natural irregularities were such that the differences
in the amounts of nitrogen by soda-lime in the subsoils
of the differently cropped portions cannot be referred to
the differences in crop history ; but, as before pointed
out, the significance of the difference in the amounts of
nitrogen as nitric acid at the different depths is much
less affected by the natural irregularities of the subsoil.
The cropping and manuring of this field are still
arranged more or less with a view to provide data in
reference of the alternation of clover with a cereal, and
the amounts of crop are, accordingly, always deter-
mined. Owing, however, to the foulness of the land
during the growth, and after the removal, of the barley
crop in 1890, it was decided to work it, and clean it
as far as possible in the autumn, and leave it for
summer fallow cleaning in 1891. It is proposed to
re-sample the soils of the different plots (especially for
the determination of nitrogen and nitric acid), in the
autumn of 1891 ; to sow barley and clover on all four
plots in 1892 ; again to sample the soils after the
removal of the clover in 1893 ; and then probably to
discontinue the experiment altogether.
The results of the experiments above described have
not been made the subject of a separate report, but
abstracts of the numerical results have been given in
several papers, and their interest and significance
pointed out. (See Nos. 38, 51, 60, 67, and 81.)
XII. EXPERIMENTS ON THE AMOUNT, AND ON THE COM-
POSITION, OF EAIN, AND OF LAND-DRAINAGE WATERS.
The rainfall has been collected and measured at
Kothamsted, almost from the commencement of the
field experiments ; for more than 38 years in a gauge of
one-thousandth of an acre area, also in an ordinary
funnel gauge of 5 inches diameter; and, commencing
49
in 1881, in an 8-inch "Board of Trade" gauge as well.
At different periods, the nitrogen as ammonia and as
nitric acid has been determined in the rain waters.
The chlorine and sulphuric acid have also frequently
been determined, and sometimes the organic nitrogen.
Three " Drain-gauges," each of one-thousandth of an
acre area, have been constructed for the determination
of the quantity, and the composition, of the water pass-
ing, respectively, through 20, 40, and 60 inches depth
of soil, with the subsoil in its natural state of consolida-
tion. These "drain-gauges" have been in operation
from September 1870 up to the present time ; the soil
having been unmanured and uncropped since 1868. In
the early years these drainage-waters were only occa-
sionally analysed, the constituents determined being the'
nitrogen as nitric acid, sometimes that as ammonia and
as organic nitrogen, and the chlorine; but from May
1877 up to the present time, the nitrogen as nitric acid,
and the chlorine, have been determined in proportionally
mixed samples of each month.
Lastly, each of the differently manured plots of the
permanent experimental wheat-field (Broadbalk) has a
separate pipe-drain, and in December 1866 most of
these, and in November 1878 the remainder, were dis-
connected from the main for the purpose of collecting
samples of the drainage water from each, for analysis.
In the early years samples were not so regularly taken
as subsequently, but from April 1878 up to the present
time, they have been collected for analysis on almost
every occasion of flow. The late Dr. Voelcker analysed
65 samples of the drainage-waters collected at different
periods, in 1866, 1867, and 1868. He determined in
them, not only the amount of nitrogen as nitric acid and as
ammonia, but he made complete analyses of the mineral
matters they contained. Of the samples collected from
1868 to 1873 inclusive, Dr. Frankland made 103
analyses, his determinations having reference chiefly to
the amount and the condition of combination of the
nitrogen, and to the amounts of carbon and of chlorine.
From 1876 up to the present time, the nitrogen as nitric
D
50
acid, sometimes that as ammonia, and the chlorine, have
been determined at Kothamsted, either in each indivi-
dual sample collected from each plot, or in mixed
samples representing several successive collections,
when these have been from continuous, or nearly con-
tinuous, rainfalls.
The results relating to the amounts, and to the com-
position, of Rain and Drainage-waters, are of great
interest and importance. Those relating to the amounts
of rain, in their bearing on the growth of different
crops, have been summarised and discussed in Nos. 1,
2, 31, 39, and 48 (Series 1). The first results relating to
the composition of rain-water were published in 1854
in No. 6 (Series 1). Some relating to the composition of
the drainage-waters collected in the experimental wheat
field are given and considered in No. 33 (1873) ; and in
No. 39 (1876), a summary relating to rainfall, drainage,
and composition of drainage, is given. In 1881-82, in
No. 57, most of the results obtained up to that date,
relating to the amount and composition of rain-water,
to the amount and composition of the drainage waters
passing through the 20, 40, and 60-inch " drain-gauges,"
and to the composition of the drainage-waters from the
experimental wheat-field plots, are recorded, and dis-
cussed in considerable detail ; and, in the separate
copies of the paper, Appendix Tables are added, which
record in detail, the about 1,500 determinations of
nitrogen as nitric acid, and of chlorine, respectively,
made in the drainage-waters from the differently
manured plots in the experimental wheat-field, collected
from December 1866 to May 1882 inclusive. Since
that date, about 2,000 determinations of nitrogen as
nitric acid, and about the same number of chlorine, also
occasionally some of ammonia, have been made, in the
drainage-waters from the different plots. In No. 63
(1883), new determinations of ammonia, chlorine, and
sulphuric acid, in rain-water are given. Lastly, the
results as to the amounts of rain, and of drainage
through the 20, 40, and 60-inch deep drain-gauges, are
given for 20 harvest-years, to August, 1890, inclusive,
51
in No. 85 ; they are each year summarised up to date
in the "Memoranda;" and there are there given, also up
to date, the amounts of nitrogen as nitric acid in the
drainage-waters.
It is a question whether a summary Table of the
amounts of nitrogen as nitric acid, and of chlorine, in
the drainage-waters from the experimental wheat-field
plots, could not be arranged for publication annually in
the " Memoranda." Probably the subject of the amount,
and the composition, of rain, and of the various
drainage-waters, might, with advantage, be again sys-
tematically treated, after a period of about 10 years
since the former detailed publication in 1881-82.
XIII. EXPERIMENTS ON THE QUESTION OF THE
FIXATION OF FREE NITROGEN.
Experiments were commenced in 1857, and were
conducted for several years in succession, to determine
whether plants assimilate free or uncombined nitrogen,
and also various collateral points.
Plants of the Gramineous, of the Leguminous, and of
other families, were grown, in closed vessels, under
sterilised conditions, supplied with pure water, washed
air, and carbonic acid ; in some cases without any
supply of combined nitrogen beyond that in the seed
sown, and in others with known quantities supplied
From the results obtained under these conditions, which
were such as to exclude any action either of electricity
or of microbes, it was concluded that, under such con-
ditions, our agricultural plants do not directly fix the
free nitrogen of the air, either by their leaves or other-
wise ; and although other experimenters have come to
an opposite conclusion from their results, we believe
that no evidence of a satisfactory and decisive character
has hitherto been adduced, which can be held as con-
clusive against the view which we have maintained as
above stated.
In recent years, however, the question has assumed
D 2
quite a new aspect. It now is, whether free nitrogen is
brought into combination by the agency of micro-
organisms, or other low forms, either within the soil
itself, or in symbiosis with a higher plant ; thus
serving indirectly as a source of nitrogen to plants of a
higher order. Considering that the results of Hellriegel
and Wilfarth on this point were, if confirmed, of great
significance and importance, it was decided to institute
experiments at Eothamsted on similar lines. Accord-
ingly, a series was undertaken in 1888; and the results
obtained clearly indicated that there was a gain of
nitrogen, beyond that supplied in the combined form,
in the soil, and in the seed sown. These first experi-
ments were, however, only initiative, and new series
were instituted in 1889 and 1890, and some of the
biennial or perennial plants are still growing, so that
complete quantitative results are not yet available;
but there can be no doubt that, in the subsequent
experiments, the evidence of fixation will be even more
marked than in those of 1888. Obviously such results
open a wide field for further investigation; and, ac-
cordingly, the enquiry is being continued and extended.
The earlier results obtained on this subject were
published, in abstract in No. 14, and in considerable
detail in Nos. 17 and 20 (Series 1) ; and they have
frequently been referred to in subsequent papers.
Other and more recent results of our own bearing upon
the question, as well as those of others published within
recent years, have been considered, in abstract in No. 75,
and more fully in No. 77. A preliminary notice of
the results obtained in the new vegetation experiments
was presented to the Eoyal Society in January 1890,
and it is proposed to discuss them and subsequent
results more fully, when the whole of the analytical
details are available. These recent experiments on
the question of the fixation of free nitrogen, were
referred to in a postscript in No. 77, also in No. 81;
No. 82 gives the " Preliminary Notice ; " and No. 84
gives a resumd of both the earlier and the later
results.
XIV. EXPERIMENTS ON THE FEEDING OF ANIMALS.
The investigations which have been conducted under
this head may be conveniently described to a great
extent in the terms in which they are referred to in
the " Memoranda."
Experiments with the animals of the farm were com-
menced early in 1847, and have been continued, at
intervals, up to the present time.
The following points have been investigated;
1. The amount of food, and of its several constituents,
consumed in relation to a given live-weight of animal
within a given time.
2. The amount of food, and of its several constituents,
consumed to produce a given amount of increase in live-
weight.
3. The proportion, and relative development, of the
different organs or parts, of different animals.
4. The proximate and ultimate composition of the
animals, in different conditions as to age and fatness,
and the probable composition of their increase in live-
weight during the fattening process.
5. The composition of the solid and liquid excreta
(the manure), in relation to that of the food consumed.
6. The loss or expenditure of constituents by respira-
tion and the cutaneous exhalations that is, in the
mere sustenance of the living meat- and manure-making
machine.
7. The influence of different descriptions of food, on
the quantity and the quality of the milk yielded by the
cow.
The general plan of experimenting was as follows :
To provide data as to the amount of food, or of its
several constituents, consumed in relation to a given
live-weight of animal within a given time, and to pro-
duce a given amount of increase in live -weight, several
hundred animals oxen, sheep, and pigs have been
experimented upon. Selected lots of animals were
supplied, for many weeks or for months consecutively,
with weighed quantities of foods, selected and allotted
54
according to the special point under enquiry. The
composition of the foods was determined by analysis.
The weights of the animals were taken, at the com-
mencement, at intervals during the progress, and at the
conclusion, of the experiment.
The amount, and the relative development, of the
different organs and parts, were determined in 2
calves, 2 heifers, 14 bullocks, 1 lamb, 249 sheep, and
59 pigs.
The percentages of water, mineral matter, fat, and
nitrogenous substance, were determined in certain sepa-
rated parts, and in the entire bodies, of 10 animals ;
namely, 1 calf, 2 oxen, 1 lamb, 4 sheep, and 2 pigs.
Complete analyses of the ashes, respectively, of the
entire carcasses, of the mixed internal and other " offal "
parts, and of the entire bodies, of each of these 10
animals, have also been made.
From the data thus provided, as to the composition
of the different descriptions of animal, in different con-
ditions as to age and fatness, the composition of the
increase whilst fattening, and the relation of the con-
stituents stored up in increase to those consumed in
food, have been estimated.
To ascertain the composition of the manure in rela-
tion to that of the food consumed, oxen, sheep, and pigs,
have been experimented upon.
In the case of oxen, the food and litter (sometimes
with an acid absorbent) were weighed, sampled, and
analysed. The animals were fed in boxes for periods
of from 5 to 9 weeks, and the total manure produced
was well mixed, weighed, sampled, and analysed. The
constituents determined in the food and litter on the
one hand, and in the manure on the other, were dry
matter, ash, and nitrogen.
In the case of sheep no litter was used ; the animals
were kept in lots of 5, on rafters, through which (but
with some little loss) the solid and liquid excreta
passed on to a sheet zinc flooring, at such an incline
that the liquid drained off into carboys containing acid,
and the solid matter was removed 2 or 3 times daily,
55
and also mixed with acid. The constituents determined
in the food and manure were dry matter, mineral
matter, sometimes " woody-fibre," and nitrogen.
In the case of pigs, individual male animals were ex-
perimented upon, each for periods of 3, 5, or 10 days
only. Each animal was kept in a frame, preventing it
from turning round, and having a zinc bottom with an
outlet for the liquid to run into a bottle, and it was
watched night and day, and the voidings carefully col-
lected as soon as passed. This could easily be done,
as the animal never passed either faeces or urine without
getting up, and in getting up he rang a bell, and so
attracted the notice of the attendant. The constituents
determined were, in the food and faeces, dry matter, ash,
and nitrogen, and in the urine, dry matter, ash, nitrogen,
and urea.
The loss or expenditure of constituents by respiration
and the cutaneous exhalations has not been determined
directly, that is by means of a respiration apparatus, but
only by difference, that is by calculation founded on the
amounts of dry matter, ash, and nitrogen r in the food,
and in the (increase) faeces and urine.
Besides the special experiments which will be
presently referred to, made to determine the influence
of different foods on the quantity and composition of
milk, a careful daily record has been kept for several
years, of the morning and evening yield of each in-
dividual, of a herd of between 40 and 50 cows, regard
being had to the amount of food consumed, which in
its turn has been to a certain extent graduated accord-
ing to the yield.
Independently of the points of enquiry above enu-
merated, the results obtained in the feeding experiments
have supplied data for the consideration of the follow-
ing questions :
1. The sources in the food of the fat produced in the
animal body.
2. The characteristic demands of the animal body
(for nitrogenous or non-nitrogenous constituents of
food), in the exercise of muscular power.
56
3. The comparative characters of animal and vege-
table food in human dietaries.
The results of the above described very compre-
hensive and very laborious experiments on the feeding
of animals, involving an elaborate investigation into
the composition of the animals fed and slaughtered as
human food, in different conditions as to age and fat-
ness, have, excepting so far as the composition of the
manure in relation to the food consumed is concerned,
been published in detail in the various papers enume-
rated in the list " Series 2 " in the Appendix.
Twelve of my Oxford Lectures were devoted to the
subject of the feeding of animals, for the production of
meat, milk, and manure, and for the exercise of force.
In the course of these lectures, the hitherto unpublished
results as to the composition of the manure in relation
to that of the food consumed, were arranged, studied,
and more or less discussed, and thus the basis of a
systematic paper on the subject has been provided.
XV. SUPPLEMENTAKY INVESTIGATIONS IN CONNECTION
WITH THE SUBJECT OF THE FEEDING OF ANIMALS.
1. Experiments on the Utilisation of Town Sewage.
In 1861, 1862, and 1863, an extensive investigation
was undertaken, in conjunction with the late Professor
Way, on behalf of the Royal Sewage Commission, of
which Sir J. B. Lawes was a member, on the application
of town sewage to different crops, but especially to grass.
The amount, and the composition, of both the sewage
applied, and the produce grown, were determined ; and,
in selected cases, the composition of the land-drainage
waters was also determined. Comparative experiments
were also made on the feeding qualities of the differently
grown produce ; the amount of increase yielded by oxen,
and the amount and the composition of the milk yielded
by cows, being determined. A large amount of the
analytical work involved was executed at Eothamsted,
bat most of it by Professor Way, in London.
57
The results of these enquiries were published in full
in No. 21, and less fully in No. 23, on the Composition,
Value, and Utilization of Town Sewage. The subject
has also been discussed in Nos. 8, 9, 19, and 26
(all in Series 2).
2. Experiments on the Malting Process, and on the Com-
parative Feeding Value of Barley and Malt.
The chemistry of the malting process, the loss of
food constituents during its progress, and the compara-
tive feeding value of barley and malt, were made the
subjects of independent experiment at Rothamsted in
1848 and 1849 ; and in 1863 and 1864, a more com-
prehensive investigation was undertaken by order of
the Board of Trade. The earlier results were discussed
in Nos. 1, 4, 12, and 13, and the later in No. 22 (Series 2).
3. Experiments on Ensilage.
Experiments were commenced in 1884, and continned
for several years, to determine the changes and losses
which food-crops undergo in the process of ensilaging,
and also the feeding value of the silage produced. With
these objects two silos were constructed.
In the first season, 1884, one silo was filled with first
and second crop red clover, and the other with first
crop meadow-grass, second crop red clover, and second
crop meadow-grass.
In the second season, 1885, Silo No. 1, was partly
filled with oats cut green, when the grain was in the
milky condition, and partly with second crop red
clover : and Silo No. 2 with first and second crop red
clover.
In the third season, 1886, first crop meadow-grass
was put into Silo No. 1 ; and into Silo No. 2, first
crop red clover, a mixed crop grown for the purpose,
consisting of beans, peas, vetches, and oats, and second
crop red clover.
In the fourth season, 1887, a similar specially grown
mixed crop of beans, peas, tares, and oats, was put
58
into Silo No. 1, but nothing into Silo No. 2 ; which,
however, still contained some of the first crop red
clover put in in 1886.
In the fifth season, 1888, meadow-grass, and half-
made meadow-hay, were put into Silo No. 1, and into
Silo No. 2, a similar mixed crop as in previous years, also
some lucerne, meadow-grass, barley cut green, and red
clover. Part of these remaining unconsumed during
the summer of 1889, and the season having been very
favourable for hay making, nothing more was put into
either silo in that year (1889). Nor was any of the
1888 silage taken out of Silo No. 1 in 1890, but in the
wet July of that year, the pit was filled up with half-
made spoiling hay, without weighing or sampling, and
the whole has been used without weighing or sampling,
so that no experimental results will be available in
regard to the contents of Silo No. 1. From Silo No.' 2,
however, the 1888 silage was removed from January to
May 1890, the whole being weighed and sampled, so
that the results will be available for purposes of calcu-
lation. Subsequently, in the summer of 1890, Silo No. 2
was also filled with half-made spoiling hay, without
weighing or sampling.
For purposes of experiment, the weight of each des-
cription of produce is taken, both when put in and
when taken out of the silo, and samples, both of the
produce as put in, and of the silage taken out, are
taken. In these, the dry matter, ash, and nitrogen,
are always determined. In the silage, in some cases,
there have also been determined, the amounts of albu-
minoid nitrogen, of soluble and insoluble nitrogenous
substance, of soluble and insoluble ash, of cellulose of
a given degree of solubility, assumed to be digestible,
and of the remaining " woody fibre," assumed to be
indigestible (though in reality largely digestible by
ruminants), also the amounts of acetic and lactic acids.
The general result is, that the loss of organic sub-
stance in the process of ensilaging is exceedingly
variable, according to the description of the herbage, its
condition of succulence or maturity, and other circum-
59
stances. The loss has, in only a few cases been but
little more than in the hay-stack, and is generally very
much more. There has always been a considerable, and
sometimes a very considerable, loss of total nitrogen ; and
there is, besides, a considerable amount of degradation
from the albuminoid condition to compounds of lower, if
of any, food-value. Nor do the results afford any evidence
that " woody-fibre " of a given degree of induration is
rendered more soluble, and consequently more digestible.
Experiments have also been made, to determine the
value as food, of different descriptions of silage, compared
with that of other ordinary food-stuffs. Thus, trials
have been made with red clover silage against a mix-
ture of red clover hay and Swedish turnips in each
case given, with fixed amounts of other foods, to fatten-
ing oxen; with red clover and meadow-grass silage,
against mangels, each given, with fixed amounts of other
foods, to milking cows ; with silaged green oats against
ripened oats (grain and straw), given, with other foods,
to fattening oxen; and with meadow-grass silage
against corresponding meadow-grass hay, given, with
other foods, to fattening oxen.
So far as it is possible to state the result of the feed-
ing experiments in a few words, it may be said that
silage, properly made, of good materials, is undoubtedly
a good food. But how far it is economical must largely
depend on at what cost of loss it has been produced ; for,
so far as can be judged from the results obtained
hitherto, its value, compared with that of fairly com-
parable foods, depends, at any rate for fattening animals,
on the amount of digestible dry substance which it
supplies ; and, as has been stated, the amount of this
which is lost in its production is very variable, and
much has still to be learnt as to the conditions under
which more or less is so lost; whilst it would seem
that, of the constituents which remain, the digestibility
and assimilability of the non-nitrogenous are not in-
creased, and those of the nitrogenous are reduced.
For milking cows also, silage, given in limited quan-
tity, is a good food. But, independently of the amounts
60
of loss or degradation of constituents above referred to,
it seems to be less appropriate for them than the usual
more succulent foods, both so far as the flow of milk,
and its quality, are concerned. The important questions
as to the effect which the extensive adoption of en-
silaging would have on the cropping and general
economy of the farm, cannot be referred to here.
The results of the first season's experiments, those of
1884-85,both as to the changes and loss in the production
of the silage, and as to the feeding experiments, have
been given, and pretty fully discussed, in No. 30,
Series 2. Those obtained in the second season have
been published in the " Agricultural Gazette" both so
far as the production of the silage and the feeding ex-
periments are concerned. But the results, both as to
the silage-production, and as to the feeding experi-
ments, of subsequent seasons, remain to be considered.
The hitherto unpublished results would form the subject
of an important contribution to existing knowledge on
the ensilage question, whenever the pressure of other
subjects may permit of time being devoted to it.
The Silos will probably be used whenever the
characters of the season are such as to render it desir-
able or convenient to preserve forage crops in that way.
But further experiments on the production and use of
silage are for the present in abeyance, and they will
probably only be again undertaken should some special
points of enquiry arise.
XVI. SUMMARY, PAPERS TO BE WRITTEN, &c.
I have now given an account, as brief as the nature
of the subject would permit, of the history, and of the
present position, of most of the investigations which
have been undertaken at Kothamsted ; and, as it is sup-
posed that the document will chiefly be of use for
reference, and a full table of contents is provided at the
commencement, it is believed that the amount of detail
given will be an advantage.
In regard to my Oxford Lectures, it may be stated,
61
that the appointment was accepted with the special
view of utilising the occasion for the preparation for
publication, in a collective, systematic, and useful form,
of an account of the then more than 40 (and now
nearer 50) years of investigation, in conjunction with
Sir J. B. Lawes, at Eothamsted ; and although I have
not neglected important results and conclusions of
others, I have, as my Syllabus shows, fully utilised the
occasion as was proposed.
The Syllabus further shows, that much of the matter
dealt with had previously been published in detail, but
that a considerable amount of new matter has also
been arranged and studied for, and more or less dis-
cussed in, the Lectures. There is thus provided the
basis for several systematic papers. In all cases,
whether the subjects had previously been reported
upon in detail or not, they have been brought, in the
lectures, into collective form and order.
Six of the courses of Oxford Lectures have been sum-
marised, each into one lecture, given at the Eoyal Agri-
cultural College, Cirencester, and these single lectures
have been published (with some additions) as under :
1. On Wheat, in No. 68 1884.
2. On Barley, in No. 71 1886.
3. On Root-crops, in No. 76 .. . . . . 1887.
4. On Potatoes, in No. 78 1888.
5. On Leguminous Crops, in No. 81 .. . . 1889.
6. On the Fixation of Free Nitrogen, in No. 84 1890.
I will now point out what seems to be the proper
order of publication on other subjects, within the com-
paratively near future.
1. As already referred to (p. 52),a" Preliminary Notice "
of the results of the experiments made at Eothamsted
in 1888 and 1889, on the lines of those of Hellriegel
and Wilfarth, to determine whether the free nitrogen of
the atmosphere contributes to the nitrogen of certain
plants, under the influence of suitable microbe infection
of the soil, was published in the " Proceedings of the
62
Royal Society " early in 1890 ; but it is hoped that this
will soon be followed by a full report, bringing the
record up to date.
2. Part III The Chemical Results in connection
with the subject -of the experiments on the Mixed
Herbage of Grass-land. This will be a long joint
paper, and it is expected that it will be ready for
publication in the course of the present year, 1891.
3. The Experiments on Eotation; including both
the Field results, and those of the Laboratory inves-
tigations connected with them. This will also be
a long joint paper ; and it should follow next in order
to No. 2.
4. Probably the results relating to the composition of
Animal manure, in relation to that of the food con-
sumed.
5. Continuation of report on the Ensilage Experi-
ments.
Besides these subjects, the preparation for publica-
tion, of the matter of the Oxford Lectures (which,
however, will not appear in the form of lectures), should
not be long delayed, and should, indeed, if possible,
proceed concurrently with that of the papers above
enumerated.
Other subjects will probably arise from time to time,
which will require attention ; and, as has been pointed
out, the continuation of systematic reports will, in the
course of time, have to be considered ; as for example
on the Wheat experiments, after 40 years, commencing
with 1852, or after the first 50 years, or after the third
period of 20 years; on the Barley experiments, after
the second period of 20 years ; on the amount and com-
position of Eain and Drainage Waters say in 10 years
after the last publication. These, and other subjects,
as has been indicated, will also be brought up to date,
in more or less detail, in the work embodying the
substance of the Oxford Lectures.
In conclusion, I may add that; of more than 700
complete ash-analyses that have been made, some have
03
been published in detail, some only partially, and
others remain to be considered. The following have
been fully written upon, and published :
40 connected with animal composition (No. 29,
Series 2).
253 of Wheat Grain and Wheat Straw (No. 65,
Series 1).
20 of Potato Tubers and Juice . . (No. 78,
Series 1).
313
Of 88 analyses of the ashes of Barley Grain and
Barley Straw, the greater number have been arranged,
and partly written upon, in the Oxford Lectures ; and
the results and discussion have been summarised in
No. 71.
Of 145 analyses of the ashes of the Mixed, or the
Separated Herbage, of Grass-land, most have been
arranged, and partly written upon, in the Oxford Lec-
tures ; and they will be fully discussed and published,
in "Part III The Chemical Results" above referred to.
60 analyses of the ashes of the Eotation produce, and
8 of the ashes of Bean-plant, are written upon in the
Oxford Lectures ; and they will be fully discussed and
published in the paper on the Eotation Experiments.
There are 68 analyses of the ash of Bean-corn and
Bean-straw, the results of which will probably also find
appropriate place in the report on the Eotation Experi-
ments ; or they may be embodied in the Work founded
on the Oxford Lectures,, in the section relating to
" Leguminous Crops ; " or they may receive separate
consideration in due course.
Lastly, there are 32 partial analyses of the ash of
Sugar-beet juice, which may perhaps be embodied in
the Work on the matter of the Oxford Lectures, in
the section relating to Eoot-crops, if not otherwise
arranged for,
G4
APPENDIX.
The following lists give the titles of Eothamsted
papers already published, arranged in two Series, and
within each Series numbered in chronological order.
They also show, both where each paper originally appeared,
and the date of its publication.
SERIES I. Reports of Field Experiments, Eperiments on
Vegetation, fyc., 8fc.
Published 1847-91 inclusive.
1. Agricultural Chemistry (Jour. Boy. Ag. Soc. Eng.,
vol. viii, p. 226) 1847
2. Agricultural Chemistry, Turnip Culture (Jour. Boy.
Ag. Soc. Eng., vol. viii, p. 494) 1847
3. Experimental Investigations into the Amount of
Water Given Off by Plants during their Growth,
especially in relation to the Fixation and Source
of their various Constituents (Jour. Hort. Soc.
Lond., vol. v, p. 38) 1850
4. Beport of some Experiments undertaken at- the
suggestion of Professor Lindley, to ascertain the
Comparative Evaporating Properties of Evergreen
and Deciduous Trees (Jour. Hort. Soc. Lond., vol.
vi, p. 227) 1851
5. Agricultural Chemistry, especially in relation to the
Mineral Theory of Baron Liebig (Jour. Boy. Ag.
Soc. Eng., vol. xii, p. 1) . . . . . . . . 1851
6. On the Amounts of, and Methods of Estimating,
Ammonia and Nitric Acid in Bain- water (Beport
of the British Association for the Advancement of
Science for 1854) 1854
7. Beport to the Bight Hon. the Earl of Leicester, on
the Experiments, conducted by Mr. Keary, on the
Growth of Wheat upon the same land for four
successive years at Holkham Park Farm (Jour.
Boy. Ag. Soc. Eng., vol. xvi, p. 207) . . . . 1855
65
8. On some points connected with Agricultural
Chemistry ; being a reply to Baron Liebig's
" Principles of Agricultural Chemistry " (Jour.
Eoy. Ag. Soc. Eng., vol. xvi, p. 411) . . . . 1855
9. On the Growth of Wheat by the Lois Weedon
System, on the Rothamsted Soil; and on the
Combined Nitrogen in Soils (Jour. Roy. Ag. Soc.
Eng., vol. xvii, p. 582) 1856
10. On some points in the Composition of Wheat Grain,
its Products in the Mill, and Bread (Journal of
the Chemical Society of London, vol. x, p. 1) . . 1857
11. On the Growth of Barley by different Manures
continuously on the Same Land ; and on the Posi-
tion of the Crop in Rotation (Jour. Roy. Ag. Soc.
Eng., vol. xviii, p. 454) 1857
12. Report of Experiments with different Manures on
Permanent Meadow Land, with Tabular Appendix
(Jour. Roy. Ag. Soc. Eng., vols. xix, p. 552, and
xx, pp. 228 and 398) 1858-59
13. Report of Experiments on the Growth of Red
Clover by different Manures (Jour. Roy. Ag. Soc.
Eng., vol. xxi, p. 178) 1860
14. On the Sources of the Nitrogen of Vegetation ; with
special reference to the question whether Plants
Assimilate Free or Uncombined Nitrogen. Ab-
stract (Proceedings of the Royal Society of
London, vol. x, p. 544) 1860
15. On the Application of Different Manures to Differ-
ent Crops, and on their proper distribution on the
Farm -. 1861
16. On some Points in connection with the Exhaustion
of Soils. Abstract (Report of the British Asso-
ciation for the Advancement of Science for
1861) 1861
17. On the Sources of the Nitrogen of Vegetation, with
special reference to the question whether Plants
Assimilate Free or Uncombined Nitrogen (Philo-
sophical Transactions, part 2, 1861) . . . . 1861
18. Report of Experiments made at Rodmersham, Kent,
on the Growth of Wlieat by different Descriptions
of Manure for several years in succession on the
same Land (Jour. Roy. Ag. Soc. Eng., vol. xxiii,
p. 31) 1862
E
66
19. The Effects of Different Manures on the Mixed
Herbage of Grass Land (Jour. Boy. Ag. Soc. Eng.,
vol. xxiv, p. 131) 1863
20. On the Sources of the Nitrogen of Vegetation, with
special reference to the question whether Plants
assimilate Free or Uncombined Nitrogen (Jour.
Chem. Soc., new series, vol. i ; entire series,
vol. xvi) 1863
21. Liebig and the "Mineral Theory" (note, extracted
from a paper by Messrs. Lawes and Gilbert, Jour.
Roy. Ag. Soc. Eng., vol. xxiv, part 2) . . . . 1863
22. Further Report of Experiments with Different
Manures on Permanent Meadow Land (Jour.
Roy. Ag. Soc. Eng., vol. xxiv, part 2) . . . . 1863
23. Report of Experiments on the growth of Wheat for
Twenty Years in Succession on the same land
(Jour. Roy. Ag. Soc. Eng., vol. xxv, parts 1 and 2) 1864
24. On the Selection of Artificial Manures for the
Sugar-cane . . . . . . . . . . . . 1864
25. On the Accumulation of the Nitrogen of Manure
in the Soil (Report of the British Association for
the Advancement of Science for 1866) . . . . 1866
26. Preliminary Notice of Results on the Composition
of Wheat grown for twenty years in succession
on the same land (Report of the British Associa-
tion for the Advancement of Science for 1867) . . 1867
27. On the Home Produce, Imports, and Consumption
of Wheat (Jour. Roy. Ag. Soc. Eng., vol. iv, s.s.,
part 2) 1868
28. Exhaustion of the Soil in Relation to Landlords'
Covenants, and the Valuation of Unexhausted
Improvements (read before the London Farmers'
Club, April 4, 1870) 1870
2.1. Scientific Agriculture with a view to Profit (read be-
fore the Maidstone Farmers' Club, Dec. 15, 1870) 1870
30. Reports of Experiments on the Influence of various
Manures on different Species of Plants (Proceed-
ings of the Royal Horticultural Society) . . . . 1870
31. Effects of the Drought of 1870 on some of the
Experimental Crops at Rothamsted) Jour. Roy.
Ag. Soc. Eng., vol. vii, s.s., part 1) . . . . 1871
32. Notes on Clover Sickness (Jour. Roy. Hort. Soc.,
vol. iii) . . 1871
67
33. Report of Experiments on the Growth of Barley
for Twenty Years in Succession on the same laud
(Jour. Roy.Ag. Soc.Eng.,vol.ix, s.s., parts 1 and 2) 1873
34. Unexhausted Tillages and Manures, with reference
to the Landlord and Tenant (Ireland) Act, 1870 1874
35. On the more frequent Growth of Barley on Heavy
Land (read before the London Farmers' Club,
February 1, 1875) 1875
36. On the Valuation of Unexhausted Manures (Jour.
Roy. Ag. Soc. Eng., vol. xi, s.s., part 1) . . . . 1875
37. Note on the Occurrence of " Fairy Rings " (Jour.
Linn. Soc., Botany, vol. xv, p. 17) . . . . 1875
38. On some points in connection with Vegetation
(Address delivered at South Kensington in the
Chemical Section of the Science Conferences) . . 1876
39. On Rainfall, Evaporation, and Percolation (Proceed-
ings of the Inst. of Civil Engineers, vol. xiv, part 3) 1876
40. Freedom in the Growth and Sale of the Crops of
the Farm, considered in relation to the interests
of the Landowner and the Tenant Farmer (Jour.
Soc. Arts, December 14, 1877) 1877
41. Composition of Potatoes (Note Jour. Roy. Hort.
Soc., vol. v, part 5 ; Proceedings, p. xxxvii) . . 1878
42. On Nitrification; Reports of Experiments made in
the Rothamsted Laboratory. (Part 1, Jour. Chem.
Soc., January, 1878 ; Part 2, Jour. Chem. Soc.,
July, 1879 ; Part 3, Jour. Chem. Soc., December,
1884 ; Part 4, Jour. Chem. Soc., 1891). See also
Rep. Brit. Ass., 1881 ; Jour. Chem. Soc., Octo-
ber, 1885, February, 1887, and August, 1888 1878-91
43. Is Higher Farming a Remedy for Lower Prices ?
(Lecture delivered before the East Bewickshire
Agricultural Association, May 3, 1879. Published
by G. Macaskie, " Warder " Office, Berwick) . . 1879
44. On the Determination of Nitric Acid as Nitric
Oxide, by means of its action on Mercury ; a
Report of Experiments made in the Rothamsted
Laboratory (Jour. Chem. Soc., July, 1879) . . 1879
45. On the Determination of Nitric Acid by means of
Indigo, with special reference to Water Analysis ;
a Report of Experiments made in the Rotbamsted
Laboratory (Jour. Chem. Soc., September, 1879).
See also Chem. News, February 2 and 9, 1877 1877-79
68
46. Agricultural, Botanical, and Chemical Results of
Experiments on the Mixed Herbage of Permanent
Meadow, conducted for more than twenty years
in succession on the same Land. Part 1, The
Agricultural Results. Abstract (Proceedings of
the Royal Society, No. 197, 1879) . . . . 1879
47. On some points in connection with Agricultural
Chemistry. Abstract (Report of the British Asso-
ciation for the Advancement of Science for 1879) 1879
48. Our Climate and our Wheat- Crops (Jour. Roy.
Ag. Soc. Eng., vol. xvi, s.s., part 1) . . . . 1880
49. On the Home Produce, Imports, Consumption, and
Price of Wheat, over twenty-eight (or twenty-
seven) harvest- years, 1852-53 to 1879-80 inclu-
sive (Jour, of the Statistical Society, June, 1880) 1880
50. Agricultural, Botanical, and Chemical Results of
Experiments on the Mixed Herbage of Permanent
Meadow, conducted for more than twenty years
in succession on the same Land. Part 1, The
Agricultural Results. Full Paper. (Philosophical
Transactions, part 1, 1880) . . . . . . 1880
51. Sketch of the Progress of Agricultural Chemistry:
Address to the Chemical Section of the British
Association (Report of the British Association
for the Advancement of Science for 1880) . . 1880
52. On the Determination of Nitric Acid as Nitric
Oxide by means of its reaction with Ferrous Sails.
Reports of Experiments made in the Rothamsted
Laboratory. (Part 1, Jour. Chem. Soc., July, 1880 ;
Part 2, Jour. Chem. Soc., August, 1882) 1880-82
53. On the Determination of Carbon in Soils ; a Report
of Experiments made in the Rothamsted Labora-
tory (Jour. Chem. Soc., September, 1880) . . 1880
54. On the Home Produce, Imports, Consumption, and
Price of Wheat, over twenty-seven (or twenty-
eight) harvest years, 1852-53 to 1879-80 (Jour.
Roy. Ag. Soc., vol. xvi, s.s., part 2, 1880) . . 1880
55. Agricultural, Botanical, and Chemical Results of
Experiments on the Mixed Herbage of Permanent
Meadow, conducted for more than twenty years in
succession on the same land. Part 2, The Bota-
nical Results. Abstract (Proc. Roy. Soc., vol. xxx,
p. 556) . . 1880
69
56. Letter on " Bread Reform " (Journal of the Society
of Arts, January 21, 1881) 1881
57. On the Amount and Composition of the Rain and
Drainage- Waters collected at Rothamsted, parts
1, 2, and 3 (Jour. Roy. Ag. Soc. Eng., vol. xvii,
8.8. (1881), pp. 241-279, and 311-350 ; vol. xviii
(1882), pp. 1-71). In the separate copies of the
entire paper, section 3 of part 3 is given as part 4,
and Appendix Tables are also added . . 1881-82
58. Letters on " Fertility " (Agricultural Gazette, Feb.
21 and 28; Mar. 7, 14, and 21; April 4, 11, 18,
and 25 ; May 2 and 9, 1881) 1881
59. Some Practical Aspects of recent investigations on
Nitrification (Journal of the Society of Arts,
April 7, 1882) 1882
60. Determinations of Nitrogen in the Soils of some
of the Experimental Fields at Rothamsted, and
the bearing of the results on the question of
the Sources of the Nitrogen of our Crops.
(Read at the Meeting of the American Asso-
ciation for the Advancement of Science, at
Montreal, August 1882) . . 1882
61. Agricultural, Botanical, and Chemical Results of
Experiments on the Mixed Herbage of Permanent
Meadow, conducted for more than twenty years in
succession on the same land. Part 2, The
Botanical results. Full Paper. (Phil. Trans.,
part 4, 1882) ,, 1882
61a. On the Determination of Nitric Acid in Soils
(Jour. Chem. Soc.. Aug., 1882) . . ..... 1882
61b. On some of the changes which Nitrogenous Matter
undergoes within the Soil (Lecture delivered at
South Kensington, April 16, 1883) . . . . 1883
62. Contributions to the Chemistry of " Fairy Rings "
(Jour. Chem. Soc., May, 1883) 1883
63. New Determinations of Ammonia, Chlorine, and
Sulphuric Acid, in the Rain- Water collected at
Rothamsted (Jour. Roy. Ag. Soc. Eng., vol. xix,
s.s., part 2, 1883) 1883
64. The Nitrogen as Nitrio Acid, in the Soils and
Subsoils of some of the Fields at Rothamsted
(Jour. Roy. Ag. Soc., Eng., vol. xix, s.s., part 2,
1883) 1883
70
65. On the Composition of the Ash of Wheat-Grain, and
Wheat- Straw, grown at Rothamsted, in different
Seasons, and by different Manures (Jour. Chem.
Soc., August, 1884) 1884
66. Report of Experiments on the growth of Wheat for
the second period of twenty years in succession
on the same Land (Jour. Roy. Ag. Soc. Eng.,
vol. xx, s.s., part 2, 1884) 1884
67. On some points in the Composition of Soils ; with
Results illustrating the sources of the Fertility of
Manitoba Prairie Soils (Brit. Ass. for the Advance-
ment of Science, Montreal, September 2, 1884;
Abstract -T- Rep. p. 686. Full Paper Trans.
Chem. Soc., June, 1885) . . . . . . 1884-85
68. On Agricultural Investigation ; being a Lecture de-
livered at the Michigan State Agricultural College,
Lansing, Mich., October 14, 1884 ; and at Rutgers
College, New Brunswick, N.J., October 27, 1884 1884
69. Note on some conditions of the development, and of
the activity, of Chlorophyll. Abstract (Report of
the British Association for the Advancement of
Science for 1885) 1885
70. On the Valuation of Unexhausted Manures (Jour.
Roy. Ag. Soc. Eng., vol. xxi, s.s., part 2) . . 1885
71. Results of Experiments at Rothamsted on the
Growth of Barley for more than thirty years in
succession on the same Land (Agricultural
Students' Gazette, New Series, vol. iii, part 1) . . 1886
72. Remarques sur la relation qui existe entre les sommes
de temperature et la production agricole (Archives
des sciences physiques et naturelles, Troisieme
periode, Tome xvi, No. 11, Novembre 15, 1886) 1886
73. The Home Produce, Imports, Consumption and
Price of Wheat in the United Kingdom, Thirty-
four Harvest-years, 1852-63 to 1885-86 ("The
Field," February 12, 1887) 1887
74. A contribution to the Study of Well Waters (Jour.
Chem. Soc., June, 1887) 1887
75. On the present position of the question of the
Sources of the Nitrogen of Vegetation, with some
new results, and preliminary notice of new lines
of investigation. Preliminary Notice (Proc. Roy.
Soc., vol. xliii, p. 108) 1887
71
76. Results of Experiments at Rothamsted on the
Growth of Root-crops for many years in succes-
sion on the same Land (Agricultural Students'
Gazette, New Series, vol. iii, part 5) . . . . 1887
77. On the Present Position of the Question of the
Sources of Nitrogen of Vegetation, with some
new Results, and Preliminary Notice of New
Lines of Investigation. Full Paper. (Phil.
Trans., vol. clxxx (1889), B., pp. 1107) . . 1889
78. Results of Experiments at Rothamsted on the
Growth of Potatoes for twelve years in succes-
sion on the same Land (Agricultural Students'
Gazette, New Series, vol. iv, part 2) . . . . 1888
79. The History of a FieJd newly laid down to Per-
manent Grass (Jour. Roy. Ag. Soc., Eng., vol. xxv,
s.s., part 1, 1889) 1889
80. The Amount of Nitric Acid in the Rain- Water at
Rothamsted, with Notes on the Analysis of Rain-
Water (Jour. Chem. Soc., August, 1889) . . 1889
81 . Results of Experiments at Rothamsted on the
Growth of Leguminous Crops for many years
in succession on the same Land (Agricultural
Students' Gazette, New Series, vol. iv, parts 5
and 6) 1889-90
8'2. New Experiments on the question of the Fixation
of Free Nitrogen Preliminary Notice (Proc.
Roy. Soc., vol. -xlvii, p. 85) 1890
88. The Food of our Agricultural Crops (Jour. Roy.
Ag. Soc. Eng., vol. i, t.s., part 1, 1890) . . . . 1890
84. Results of Experiments at Rothamsted, on the
Question of the Fixation of Free Nitrogen
(Agricultural Students' Gazette, New Series,
vol. v, parts 2 and 3) 1890-91
85. Observations on Rainfall, Percolation and Evapora-
tion at Rothamsted, with tabular results for
Twenty Harvest-years (September 1 to August
31), 1870-71 to 1889-90, inclusive (Proceedings
of the Inst. of Civil Engineers, vol. cv, part 3) . . 1891
72
SERIES II. Reports of Experiments on the Feeding of
Animals, Sewage Utilisation, Ensilage, Sfc., fyc.
Published 1849-85, inclusive.
1. Agricultural Chemistry : Sheep Feeding and
Manure, part 1. (With Tabular Appendix in
1856.) (Jour. Roy. Ag. Soc. Eng., vol. x, p. 276) 1849
2. Report of Experiments on the Comparative Fatten-
ing Qualities of Different Breeds of Sheep
Hampshire and Sussex Downs (Jour. Roy. Ag.
Soc. Eng., vol. xii, p. 414) 1851
3. Report of Experiments on the Comparative Fatten-
ing Qualities of Different Breeds of Sheep Cots-
wolds (Jour. Roy. Ag. Soc, Eng., vol. xiii, p. 179) 1852
4. On the Composition of Foods in relation to Respira-
tion and the Feeding of Animals (Report of the
British Association for the Advancement of Science
for 1852) 1852
5. Agricultural Chemistry : Pig Feeding (Jour. Roy.
Ag. Soc. Eng., vol. xiv, p. 459) . . . . . . 1853
6. On the Equivalency of Starch and Sugar in Food
(Report of the British Association for the
Advancement of Science for 1854) . . . . 1854
7. Experiments on the Comparative Fattening Quali-
ties of Different Breeds of Sheep Leicesters and
Cross-Breeds (Jour. Roy. Ag. Soc, Eng., vol. xvi,
p. 45) 1855
8. On the Sewage of London (Journal of the Society
of Arts, March 7, 1855) 1855
9. Letter on the Utilisation of Town Sewage (from the
Report ordered by the House of Commons to be
printed, August 3, 1857. Appendix xii, p. 477) 1857
10. Experimental Inquiry into the Composition of some
of the Animals Fed and Slaughtered as Human
Food. Abstract (Proceedings of the Royal Society
of London, vol. ix, p. 348) . . . . . . . . 1858
11. Observations on the recently-introduced Manufac-
tured Foods for Agricultural Stock (Jour. Roy.
Ag. Soc. Eng., vol. xix, p. 199) 1858
12. Experimental Inquiry into the Composition of some
of the Animals Fed and Slaughtered as Human
Food (Philosophical Transactions, part 2, 1859) 1859
73
13. On the Composition of Oxen, Sheep, and Pigs, and
of their Increase while Fattening (Jour. Roy. Ag.
Soc. Eng., vol. xxi, p. 433) 1860
14. On the Composition of the Animal Portion of our
Food, and on its relations to Bread. Abstract
(Jour. Chem. Soc., vol. xii, p. 54). . . . . . 1860
15. Fifth Report of Experiments on the Feeding of
Sheep (Jour. Roy. Ag. Soc. Eng., vol. xxii,
p. 189) 1861
16. Report of Experiments on the Fattening of Oxen
at Woburn Park Farm (Jour. Roy. Ag. Soc. Eng.,
vol. xxii, p. 200) 1861
17. Experiments on the Question whether the Use of
Condiments increases the Assimilation of Food
by Fattening Animals, or adds to the Profits of
the Feeder (Edinburgh Vetei'inary Review and
Annals of Comparative Pathology, July, 1862) . . 1862
18. Supplementary Report of Experiments on the
Feeding of Sheep (Jour. Roy. Ag. Soc. Eng., vol.
xxiii, p. 191).. 1862
19. The Utilisation of Town Sewage (Jour. Roy. Ag.
Soc. Eng., vol. xxiv, p. 65). . , . . . . . . 1863
20. On the Chemistry of the Feeding of Animals for
the Production of Meat and Manure (read before
the Royal Dublin Society, March 31, 1864) . . 1864
21. On the Sewage of Towns (Third Report and Ap-
pendices 1, 2, and 3 of the Royal Commission.
Presented to Parliament) . . . . . . . . 1865
22. Report (presented to Parliament) of Experiments
undertaken by Order of the Board of Trade to
Determine the Relative Values of Unmalted and
Malted Barley as Food for Stock 1866
23. On the Composition, Value, and Utilisation of Town
Sewage (Jour. Chem. Soc., New Series, vol. iv;
Entire Series, vol. xix) 1866
24. Food, in its Relations to the various Exigencies of
the Animal Body (Phil. Mag., July, 1866) . . 1866
25. On the Sources of the Fat of the Animal Body
(Abstract Rep. Brit. Ass. for 1866. Full paper,
Phil. Mag., Dec., 1866) 1866
26. Note On Sewage Utilisation (Proceedings of
the Institution of Civil Engineers, vol. xiv,
part 3) ]876
27. On some points in connection with Animal Nutrition
(Address delivered at South Kensington in the
Biological Section of the Science Conferences). . 1876
28. On the Formation of Fat in the Animal Body
(Journal of Anatomy and Physiology, vol. xi,
part 4) 1877
29. Supplement to former Paper entitled " Experi-
mental Inquiry into the Composition of some of
the Animals Fed and Slaughtered as Human
Food" Composition of the Ash of the Entire
Animals, and of certain Separated Parts (Abstract
Proc. Roy. Soc., vol. xxxv. Full Paper Philo-
sophical Transactions, part 3, 1883) . . . . 1883
30. Experiments on Ensilage conducted at Bothamsted,
Season 1884-85 , 1885
soN AND SONS Printers in Ordinary to Her Majesty, St. Martin's Lan*
,
Author Gilbert, J. H.
b!067
Agric
Title History and present position of the Rotharasted
i mva Q+ t era + \ r ft a
DATE.
NAME OF BORROWER.